diff --git a/executor/aggfuncs/func_max_min_test.go b/executor/aggfuncs/func_max_min_test.go
index 54ce66f9e6531..04be5a4b4b923 100644
--- a/executor/aggfuncs/func_max_min_test.go
+++ b/executor/aggfuncs/func_max_min_test.go
@@ -24,6 +24,59 @@ import (
 	"github.com/pingcap/tidb/util/chunk"
 )
 
+func (s *testSuite) TestMergePartialResult4MaxDecimal(c *C) {
+	srcChk := chunk.NewChunkWithCapacity([]*types.FieldType{types.NewFieldType(mysql.TypeNewDecimal)}, 5)
+	for i := int64(0); i < 5; i++ {
+		srcChk.AppendMyDecimal(0, types.NewDecFromInt(i))
+	}
+	iter := chunk.NewIterator4Chunk(srcChk)
+
+	desc := &aggregation.AggFuncDesc{
+		Name:  ast.AggFuncMax,
+		Mode:  aggregation.CompleteMode,
+		Args:  []expression.Expression{&expression.Column{RetType: types.NewFieldType(mysql.TypeLonglong), Index: 0}},
+		RetTp: types.NewFieldType(mysql.TypeNewDecimal),
+	}
+	finalDesc := desc.Split([]int{0})
+
+	// build max func for partial phase.
+	partialMaxFunc := aggfuncs.Build(s.ctx, desc, 0)
+	partialPr1 := partialMaxFunc.AllocPartialResult()
+	partialPr2 := partialMaxFunc.AllocPartialResult()
+
+	// build final func for final phase.
+	finalMaxFunc := aggfuncs.Build(s.ctx, finalDesc, 0)
+	finalPr := finalMaxFunc.AllocPartialResult()
+	resultChk := chunk.NewChunkWithCapacity([]*types.FieldType{types.NewFieldType(mysql.TypeNewDecimal)}, 1)
+
+	// update partial result.
+	for row := iter.Begin(); row != iter.End(); row = iter.Next() {
+		partialMaxFunc.UpdatePartialResult(s.ctx, []chunk.Row{row}, partialPr1)
+	}
+	partialMaxFunc.AppendFinalResult2Chunk(s.ctx, partialPr1, resultChk)
+	c.Assert(resultChk.GetRow(0).GetMyDecimal(0).Compare(types.NewDecFromInt(4)) == 0, IsTrue)
+
+	row := iter.Begin()
+	row = iter.Next()
+	for row = iter.Next(); row != iter.End(); row = iter.Next() {
+		partialMaxFunc.UpdatePartialResult(s.ctx, []chunk.Row{row}, partialPr2)
+	}
+	resultChk.Reset()
+	partialMaxFunc.AppendFinalResult2Chunk(s.ctx, partialPr2, resultChk)
+	c.Assert(resultChk.GetRow(0).GetMyDecimal(0).Compare(types.NewDecFromInt(4)) == 0, IsTrue)
+
+	// merge two partial results.
+	err := finalMaxFunc.MergePartialResult(s.ctx, partialPr1, finalPr)
+	c.Assert(err, IsNil)
+	err = finalMaxFunc.MergePartialResult(s.ctx, partialPr2, finalPr)
+	c.Assert(err, IsNil)
+
+	resultChk.Reset()
+	err = finalMaxFunc.AppendFinalResult2Chunk(s.ctx, finalPr, resultChk)
+	c.Assert(err, IsNil)
+	c.Assert(resultChk.GetRow(0).GetMyDecimal(0).Compare(types.NewDecFromInt(4)) == 0, IsTrue)
+}
+
 func (s *testSuite) TestMergePartialResult4MaxFloat(c *C) {
 	srcChk := chunk.NewChunkWithCapacity([]*types.FieldType{types.NewFieldType(mysql.TypeDouble)}, 5)
 	for i := int64(0); i < 5; i++ {
@@ -76,3 +129,113 @@ func (s *testSuite) TestMergePartialResult4MaxFloat(c *C) {
 	c.Assert(err, IsNil)
 	c.Assert(resultChk.GetRow(0).GetFloat64(0) == float64(4), IsTrue)
 }
+
+func (s *testSuite) TestMergePartialResult4MinDecimal(c *C) {
+	srcChk := chunk.NewChunkWithCapacity([]*types.FieldType{types.NewFieldType(mysql.TypeNewDecimal)}, 5)
+	for i := int64(0); i < 5; i++ {
+		srcChk.AppendMyDecimal(0, types.NewDecFromInt(i))
+	}
+	iter := chunk.NewIterator4Chunk(srcChk)
+
+	desc := &aggregation.AggFuncDesc{
+		Name:  ast.AggFuncMin,
+		Mode:  aggregation.CompleteMode,
+		Args:  []expression.Expression{&expression.Column{RetType: types.NewFieldType(mysql.TypeLonglong), Index: 0}},
+		RetTp: types.NewFieldType(mysql.TypeNewDecimal),
+	}
+	finalDesc := desc.Split([]int{0})
+
+	// build min func for partial phase.
+	partialMinFunc := aggfuncs.Build(s.ctx, desc, 0)
+	partialPr1 := partialMinFunc.AllocPartialResult()
+	partialPr2 := partialMinFunc.AllocPartialResult()
+
+	// build final func for final phase.
+	finalMinFunc := aggfuncs.Build(s.ctx, finalDesc, 0)
+	finalPr := finalMinFunc.AllocPartialResult()
+	resultChk := chunk.NewChunkWithCapacity([]*types.FieldType{types.NewFieldType(mysql.TypeNewDecimal)}, 1)
+
+	// update partial result.
+	for row := iter.Begin(); row != iter.End(); row = iter.Next() {
+		partialMinFunc.UpdatePartialResult(s.ctx, []chunk.Row{row}, partialPr1)
+	}
+	partialMinFunc.AppendFinalResult2Chunk(s.ctx, partialPr1, resultChk)
+	c.Assert(resultChk.GetRow(0).GetMyDecimal(0).Compare(types.NewDecFromInt(0)) == 0, IsTrue)
+
+	row := iter.Begin()
+	row = iter.Next()
+	for row = iter.Next(); row != iter.End(); row = iter.Next() {
+		partialMinFunc.UpdatePartialResult(s.ctx, []chunk.Row{row}, partialPr2)
+	}
+	resultChk.Reset()
+	partialMinFunc.AppendFinalResult2Chunk(s.ctx, partialPr2, resultChk)
+	// Min in [2,3,4] -> 2
+	c.Assert(resultChk.GetRow(0).GetMyDecimal(0).Compare(types.NewDecFromInt(2)) == 0, IsTrue)
+
+	// merge two partial results.
+	err := finalMinFunc.MergePartialResult(s.ctx, partialPr1, finalPr)
+	c.Assert(err, IsNil)
+	err = finalMinFunc.MergePartialResult(s.ctx, partialPr2, finalPr)
+	c.Assert(err, IsNil)
+
+	resultChk.Reset()
+	err = finalMinFunc.AppendFinalResult2Chunk(s.ctx, finalPr, resultChk)
+	c.Assert(err, IsNil)
+	// Min in [0,1,2,3,4] -> 0
+	c.Assert(resultChk.GetRow(0).GetMyDecimal(0).Compare(types.NewDecFromInt(0)) == 0, IsTrue)
+}
+
+func (s *testSuite) TestMergePartialResult4MinFloat(c *C) {
+	srcChk := chunk.NewChunkWithCapacity([]*types.FieldType{types.NewFieldType(mysql.TypeDouble)}, 5)
+	for i := int64(0); i < 5; i++ {
+		srcChk.AppendFloat64(0, float64(i))
+	}
+	iter := chunk.NewIterator4Chunk(srcChk)
+
+	desc := &aggregation.AggFuncDesc{
+		Name:  ast.AggFuncMin,
+		Mode:  aggregation.CompleteMode,
+		Args:  []expression.Expression{&expression.Column{RetType: types.NewFieldType(mysql.TypeDouble), Index: 0}},
+		RetTp: types.NewFieldType(mysql.TypeDouble),
+	}
+	finalDesc := desc.Split([]int{0})
+
+	// build min func for partial phase.
+	partialMinFunc := aggfuncs.Build(s.ctx, desc, 0)
+	partialPr1 := partialMinFunc.AllocPartialResult()
+	partialPr2 := partialMinFunc.AllocPartialResult()
+
+	// build final func for final phase.
+	finalMinFunc := aggfuncs.Build(s.ctx, finalDesc, 0)
+	finalPr := finalMinFunc.AllocPartialResult()
+	resultChk := chunk.NewChunkWithCapacity([]*types.FieldType{types.NewFieldType(mysql.TypeDouble)}, 1)
+
+	// update partial result.
+	for row := iter.Begin(); row != iter.End(); row = iter.Next() {
+		partialMinFunc.UpdatePartialResult(s.ctx, []chunk.Row{row}, partialPr1)
+	}
+	partialMinFunc.AppendFinalResult2Chunk(s.ctx, partialPr1, resultChk)
+	c.Assert(resultChk.GetRow(0).GetFloat64(0) == float64(0), IsTrue)
+
+	row := iter.Begin()
+	row = iter.Next()
+	for row = iter.Next(); row != iter.End(); row = iter.Next() {
+		partialMinFunc.UpdatePartialResult(s.ctx, []chunk.Row{row}, partialPr2)
+	}
+	resultChk.Reset()
+	partialMinFunc.AppendFinalResult2Chunk(s.ctx, partialPr2, resultChk)
+	// Min in [2.0,3.0,4.0] -> 0
+	c.Assert(resultChk.GetRow(0).GetFloat64(0) == float64(2), IsTrue)
+
+	// merge two partial results.
+	err := finalMinFunc.MergePartialResult(s.ctx, partialPr1, finalPr)
+	c.Assert(err, IsNil)
+	err = finalMinFunc.MergePartialResult(s.ctx, partialPr2, finalPr)
+	c.Assert(err, IsNil)
+
+	resultChk.Reset()
+	err = finalMinFunc.AppendFinalResult2Chunk(s.ctx, finalPr, resultChk)
+	c.Assert(err, IsNil)
+	// Min in [0.0,1.0,2.0,3.0,4.0] -> 0
+	c.Assert(resultChk.GetRow(0).GetFloat64(0) == float64(0), IsTrue)
+}