diff --git a/dm/pkg/binlog/position.go b/dm/pkg/binlog/position.go
index 9573f2292fe..ad7cfb1e719 100644
--- a/dm/pkg/binlog/position.go
+++ b/dm/pkg/binlog/position.go
@@ -401,9 +401,18 @@ func (l *Location) ResetSuffix() {
 // SetGTID set new gtid for location
 // Use this func instead of GITSet.Set to avoid change other location.
 func (l *Location) SetGTID(gset gmysql.GTIDSet) error {
-	flavor := gmysql.MySQLFlavor
-	if _, ok := l.gtidSet.(*gtid.MariadbGTIDSet); ok {
+	var flavor string
+
+	switch gset.(type) {
+	case *gmysql.MysqlGTIDSet:
+		flavor = gmysql.MySQLFlavor
+	case *gmysql.MariadbGTIDSet:
 		flavor = gmysql.MariaDBFlavor
+	case nil:
+		l.gtidSet = nil
+		return nil
+	default:
+		return fmt.Errorf("unknown GTIDSet type: %T", gset)
 	}
 
 	newGTID := gtid.MinGTIDSet(flavor)
diff --git a/dm/pkg/binlog/position_test.go b/dm/pkg/binlog/position_test.go
index 715451718fb..a61996f94b7 100644
--- a/dm/pkg/binlog/position_test.go
+++ b/dm/pkg/binlog/position_test.go
@@ -763,6 +763,30 @@ func (t *testPositionSuite) TestSetGTID(c *C) {
 	c.Assert(loc.gtidSet.String(), Equals, GTIDSetStr2)
 	c.Assert(loc2.gtidSet.String(), Equals, GTIDSetStr)
 	c.Assert(CompareLocation(loc, loc2, true), Equals, 1)
+
+	loc2.gtidSet = nil
+	err = loc2.SetGTID(mysqlSet)
+	c.Assert(err, IsNil)
+	c.Assert(loc2.gtidSet.String(), Equals, GTIDSetStr)
+}
+
+func (t *testPositionSuite) TestSetGTIDMariaDB(c *C) {
+	gSetStr := "1-1-1,2-2-2"
+	gSet, err := gtid.ParserGTID("mariadb", gSetStr)
+	c.Assert(err, IsNil)
+	gSetOrigin := gSet.Origin()
+
+	loc := Location{
+		Position: gmysql.Position{
+			Name: "mysql-bin.00002",
+			Pos:  2333,
+		},
+		gtidSet: nil,
+		Suffix:  0,
+	}
+	err = loc.SetGTID(gSetOrigin)
+	c.Assert(err, IsNil)
+	c.Assert(loc.gtidSet.String(), Equals, gSetStr)
 }
 
 func (t *testPositionSuite) TestExtractSuffix(c *C) {
diff --git a/dm/syncer/binlog_locations.go b/dm/syncer/binlog_locations.go
index 2d0a29c1cbe..f73630015fc 100644
--- a/dm/syncer/binlog_locations.go
+++ b/dm/syncer/binlog_locations.go
@@ -18,11 +18,12 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/go-mysql-org/go-mysql/mysql"
 	"github.com/go-mysql-org/go-mysql/replication"
 	"go.uber.org/zap"
 
 	"github.com/pingcap/tiflow/dm/pkg/binlog"
+	"github.com/pingcap/tiflow/dm/pkg/binlog/event"
+	"github.com/pingcap/tiflow/dm/pkg/gtid"
 	"github.com/pingcap/tiflow/dm/pkg/log"
 )
 
@@ -33,7 +34,8 @@ type locationRecorder struct {
 	//       |                       |
 	// curStartLocation        curEndLocation
 	// there may be more events between curStartLocation and curEndLocation due to the limitation of binlog or
-	// implementation of DM, but those events should always belong to one transaction.
+	// implementation of DM, but in such scenario, those events should always belong to one transaction.
+	// When curStartLocation is equal to curEndLocation, it means current event is not a data change.
 	//
 	// curStartLocation is used when
 	// - display a meaningful location
@@ -44,7 +46,7 @@ type locationRecorder struct {
 	curStartLocation binlog.Location
 	curEndLocation   binlog.Location
 
-	// txnEndLocation is the end location of last transaction. If current event is the last event of a txn,
+	// txnEndLocation is the end location of last seen transaction. If current event is the last event of a txn,
 	// txnEndLocation will be assigned from curEndLocation
 	// it is used when
 	// - reset binlog replication for a finer granularity
@@ -55,15 +57,20 @@ type locationRecorder struct {
 	// distinguish DML query event.
 	inDML bool
 
+	// we assign startGTID := endGTID after COMMIT, so at COMMIT we turn on the flag.
+	needUpdateStartGTID bool
+
 	mu sync.Mutex // guard curEndLocation because Syncer.printStatus is reading it from another goroutine.
 }
 
 func (l *locationRecorder) reset(loc binlog.Location) {
 	l.mu.Lock()
 	defer l.mu.Unlock()
-	l.curStartLocation = loc
-	l.curEndLocation = loc
-	l.txnEndLocation = loc
+	// need to clone location to avoid the modification leaking outside
+	clone := loc.Clone()
+	l.curStartLocation = clone
+	l.curEndLocation = clone
+	l.txnEndLocation = clone
 }
 
 //nolint:unused
@@ -102,8 +109,13 @@ func shouldUpdatePos(e *replication.BinlogEvent) bool {
 	return true
 }
 
-func (l *locationRecorder) setCurrentGTID(gset mysql.GTIDSet) {
-	err := l.curEndLocation.SetGTID(gset)
+func (l *locationRecorder) updateCurStartGTID() {
+	gsetWrapped := l.curEndLocation.GetGTID()
+	if gsetWrapped == nil {
+		return
+	}
+	gset := gsetWrapped.Origin()
+	err := l.curStartLocation.SetGTID(gset)
 	if err != nil {
 		log.L().DPanic("failed to set GTID set",
 			zap.Any("GTID set", gset),
@@ -111,6 +123,40 @@ func (l *locationRecorder) setCurrentGTID(gset mysql.GTIDSet) {
 	}
 }
 
+func (l *locationRecorder) setCurEndGTID(e *replication.BinlogEvent) {
+	gtidStr, err := event.GetGTIDStr(e)
+	if err != nil {
+		log.L().DPanic("failed to get GTID from event",
+			zap.Any("event", e),
+			zap.Error(err))
+		return
+	}
+
+	gset := l.curEndLocation.GetGTID()
+
+	if gset == nil {
+		gset, _ = gtid.ParserGTID("", gtidStr)
+		_ = l.curEndLocation.SetGTID(gset.Origin())
+		return
+	}
+
+	clone := gset.Clone()
+	err = clone.Update(gtidStr)
+	if err != nil {
+		log.L().DPanic("failed to update GTID set",
+			zap.String("GTID", gtidStr),
+			zap.Error(err))
+		return
+	}
+
+	err = l.curEndLocation.SetGTID(clone.Origin())
+	if err != nil {
+		log.L().DPanic("failed to set GTID set",
+			zap.String("GTID", gtidStr),
+			zap.Error(err))
+	}
+}
+
 // update maintains the member of locationRecorder as their definitions.
 // - curStartLocation is assigned to curEndLocation
 // - curEndLocation is tried to be updated in-place
@@ -119,7 +165,13 @@ func (l *locationRecorder) update(e *replication.BinlogEvent) {
 	l.mu.Lock()
 	defer l.mu.Unlock()
 
-	l.curStartLocation = l.curEndLocation
+	// GTID part is maintained separately
+	l.curStartLocation.Position = l.curEndLocation.Position
+
+	if l.needUpdateStartGTID {
+		l.updateCurStartGTID()
+		l.needUpdateStartGTID = false
+	}
 
 	if !shouldUpdatePos(e) {
 		return
@@ -138,11 +190,18 @@ func (l *locationRecorder) update(e *replication.BinlogEvent) {
 	l.curEndLocation.Position.Pos = e.Header.LogPos
 
 	switch ev := e.Event.(type) {
+	case *replication.GTIDEvent:
+		l.setCurEndGTID(e)
+	case *replication.MariadbGTIDEvent:
+		l.setCurEndGTID(e)
+		if !ev.IsDDL() {
+			l.inDML = true
+		}
 	case *replication.XIDEvent:
 		// for transactional engines like InnoDB, COMMIT is xid event
-		l.setCurrentGTID(ev.GSet)
 		l.saveTxnEndLocation()
 		l.inDML = false
+		l.needUpdateStartGTID = true
 	case *replication.QueryEvent:
 		query := strings.TrimSpace(string(ev.Query))
 		switch query {
@@ -159,13 +218,9 @@ func (l *locationRecorder) update(e *replication.BinlogEvent) {
 		if l.inDML {
 			return
 		}
+		l.needUpdateStartGTID = true
 
-		l.setCurrentGTID(ev.GSet)
 		l.saveTxnEndLocation()
-	case *replication.MariadbGTIDEvent:
-		if !ev.IsDDL() {
-			l.inDML = true
-		}
 	}
 }
 
diff --git a/dm/syncer/binlog_locations_test.go b/dm/syncer/binlog_locations_test.go
index 326c3dd7626..4df4260a7c0 100644
--- a/dm/syncer/binlog_locations_test.go
+++ b/dm/syncer/binlog_locations_test.go
@@ -47,7 +47,7 @@ type testLocationSuite struct {
 	currGSet gtid.Set
 }
 
-func (s *testLocationSuite) SetUpSuite(c *C) {
+func (s *testLocationSuite) SetUpTest(c *C) {
 	s.serverID = 101
 	s.binlogFile = "mysql-bin.000001"
 	s.nextBinlogFile = "mysql-bin.000002"
@@ -55,7 +55,7 @@ func (s *testLocationSuite) SetUpSuite(c *C) {
 	s.flavor = mysql.MySQLFlavor
 	s.prevGSetStr = "3ccc475b-2343-11e7-be21-6c0b84d59f30:1-14"
 	s.lastGTIDStr = "3ccc475b-2343-11e7-be21-6c0b84d59f30:14"
-	s.currGSetStr = "3ccc475b-2343-11e7-be21-6c0b84d59f30:1-14"
+	s.currGSetStr = "3ccc475b-2343-11e7-be21-6c0b84d59f30:1-15"
 
 	var err error
 	s.prevGSet, err = gtid.ParserGTID(s.flavor, s.prevGSetStr)
@@ -179,10 +179,20 @@ func (s *testLocationSuite) checkOneTxnEvents(c *C, events []*replication.Binlog
 	c.Assert(r.curEndLocation, DeepEquals, expected[0])
 	c.Assert(r.txnEndLocation, DeepEquals, expected[0])
 
+	seenGTID := false
 	for i, e := range events {
 		r.update(e)
 		c.Assert(r.curStartLocation, DeepEquals, expected[i])
-		c.Assert(r.curEndLocation, DeepEquals, expected[i+1])
+
+		if e.Header.EventType == replication.GTID_EVENT || e.Header.EventType == replication.MARIADB_GTID_EVENT {
+			seenGTID = true
+		}
+		if seenGTID {
+			c.Assert(r.curEndLocation.Position, DeepEquals, expected[i+1].Position)
+			c.Assert(r.curEndLocation.GetGTID(), DeepEquals, expected[len(expected)-1].GetGTID())
+		} else {
+			c.Assert(r.curEndLocation, DeepEquals, expected[i+1])
+		}
 
 		if i == len(events)-1 {
 			switch e.Header.EventType {
@@ -197,7 +207,8 @@ func (s *testLocationSuite) checkOneTxnEvents(c *C, events []*replication.Binlog
 	}
 }
 
-func (s *testLocationSuite) generateExpectLocations(
+// generateExpectedLocations generates binlog position part of location from given event.
+func (s *testLocationSuite) generateExpectedLocations(
 	initLoc binlog.Location,
 	events []*replication.BinlogEvent,
 ) []binlog.Location {
@@ -224,7 +235,7 @@ func (s *testLocationSuite) TestDMLUpdateLocationsGTID(c *C) {
 	// we have 8 events
 	c.Assert(events, HasLen, 8)
 
-	expected := s.generateExpectLocations(s.loc, events)
+	expected := s.generateExpectedLocations(s.loc, events)
 
 	c.Assert(expected[8].SetGTID(s.currGSet.Origin()), IsNil)
 
@@ -246,7 +257,7 @@ func (s *testLocationSuite) TestDMLUpdateLocationsPos(c *C) {
 	events[7].Event.(*replication.XIDEvent).GSet = nil
 	events = append(events[:2], events[4:]...)
 
-	expected := s.generateExpectLocations(loc, events)
+	expected := s.generateExpectedLocations(loc, events)
 
 	s.checkOneTxnEvents(c, events, expected)
 }
@@ -257,7 +268,7 @@ func (s *testLocationSuite) TestDDLUpdateLocationsGTID(c *C) {
 	// we have 5 events
 	c.Assert(events, HasLen, 5)
 
-	expected := s.generateExpectLocations(s.loc, events)
+	expected := s.generateExpectedLocations(s.loc, events)
 
 	c.Assert(expected[5].SetGTID(s.currGSet.Origin()), IsNil)
 
@@ -281,7 +292,7 @@ func (s *testLocationSuite) TestDDLUpdateLocationsPos(c *C) {
 	events = append(events[:2], events[4:]...)
 
 	// now we have 3 events, test about their 4 locations
-	expected := s.generateExpectLocations(loc, events)
+	expected := s.generateExpectedLocations(loc, events)
 
 	s.checkOneTxnEvents(c, events, expected)
 }
@@ -305,7 +316,7 @@ func (s *testLocationSuite) TestDMLQueryUpdateLocationsGTID(c *C) {
 	// we have 7 events
 	c.Assert(events, HasLen, 7)
 
-	expected := s.generateExpectLocations(s.loc, events)
+	expected := s.generateExpectedLocations(s.loc, events)
 
 	c.Assert(expected[7].SetGTID(s.currGSet.Origin()), IsNil)
 
@@ -334,7 +345,7 @@ func (s *testLocationSuite) TestRotateEvent(c *C) {
 
 	nextLoc := s.loc
 	nextLoc.Position.Name = s.nextBinlogFile
-	expected := s.generateExpectLocations(nextLoc, events)
+	expected := s.generateExpectedLocations(nextLoc, events)
 
 	// reset events of first binlog file
 	expected[0].Position.Name = s.binlogFile
diff --git a/dm/syncer/syncer.go b/dm/syncer/syncer.go
index 9f005e7e993..6ba6cf5e487 100644
--- a/dm/syncer/syncer.go
+++ b/dm/syncer/syncer.go
@@ -1794,10 +1794,6 @@ func (s *Syncer) Run(ctx context.Context) (err error) {
 
 		startTime := time.Now()
 		e, err = s.getEvent(tctx, currentLocation)
-		s.tctx.L().Debug("location refactor",
-			zap.Stringer("current", currentLocation),
-			zap.Stringer("start", startLocation),
-			zap.Stringer("last", lastLocation))
 
 		failpoint.Inject("SafeModeExit", func(val failpoint.Value) {
 			if intVal, ok := val.(int); ok && intVal == 1 {
@@ -3684,8 +3680,6 @@ func (s *Syncer) getEvent(tctx *tcontext.Context, startLocation binlog.Location)
 	e, err := s.streamerController.GetEvent(tctx)
 	if err == nil {
 		s.locations.update(e)
-		// TODO: observe below log in integration test
-		s.tctx.L().Debug("location refactor", zap.Stringer("locations", s.locations))
 	}
 	return e, err
 }