diff --git a/library/src/main/java/com/orm/util/MultiDexHelper.java b/library/src/main/java/com/orm/util/MultiDexHelper.java
new file mode 100644
index 00000000..37b57894
--- /dev/null
+++ b/library/src/main/java/com/orm/util/MultiDexHelper.java
@@ -0,0 +1,106 @@
+package com.orm.util;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
+import android.os.Build;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.List;
+
+import dalvik.system.DexFile;
+
+/**
+ * Created by xudshen@hotmail.com on 14/11/13.
+ */
+
+//http://stackoverflow.com/a/26892658
+public class MultiDexHelper {
+    private static final String EXTRACTED_NAME_EXT = ".classes";
+    private static final String EXTRACTED_SUFFIX = ".zip";
+
+    private static final String SECONDARY_FOLDER_NAME = "code_cache" + File.separator +
+            "secondary-dexes";
+
+    private static final String PREFS_FILE = "multidex.version";
+    private static final String KEY_DEX_NUMBER = "dex.number";
+
+    private static SharedPreferences getMultiDexPreferences(Context context) {
+        return context.getSharedPreferences(PREFS_FILE,
+                Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB
+                        ? Context.MODE_PRIVATE
+                        : Context.MODE_PRIVATE | Context.MODE_MULTI_PROCESS);
+    }
+
+    /**
+     * get all the dex path
+     *
+     * @param context the application context
+     * @return all the dex path
+     * @throws PackageManager.NameNotFoundException
+     * @throws IOException
+     */
+    public static List<String> getSourcePaths(Context context) throws PackageManager.NameNotFoundException, IOException {
+        ApplicationInfo applicationInfo = context.getPackageManager().getApplicationInfo(context.getPackageName(), 0);
+        File sourceApk = new File(applicationInfo.sourceDir);
+        File dexDir = new File(applicationInfo.dataDir, SECONDARY_FOLDER_NAME);
+
+        List<String> sourcePaths = new ArrayList<String>();
+        sourcePaths.add(applicationInfo.sourceDir); //add the default apk path
+
+        //the prefix of extracted file, ie: test.classes
+        String extractedFilePrefix = sourceApk.getName() + EXTRACTED_NAME_EXT;
+        //the total dex numbers
+        int totalDexNumber = getMultiDexPreferences(context).getInt(KEY_DEX_NUMBER, 1);
+
+        for (int secondaryNumber = 2; secondaryNumber <= totalDexNumber; secondaryNumber++) {
+            //for each dex file, ie: test.classes2.zip, test.classes3.zip...
+            String fileName = extractedFilePrefix + secondaryNumber + EXTRACTED_SUFFIX;
+            File extractedFile = new File(dexDir, fileName);
+            if (extractedFile.isFile()) {
+                sourcePaths.add(extractedFile.getAbsolutePath());
+                //we ignore the verify zip part
+            } else {
+                throw new IOException("Missing extracted secondary dex file '" +
+                        extractedFile.getPath() + "'");
+            }
+        }
+
+        return sourcePaths;
+    }
+
+    /**
+     * get all the classes name in "classes.dex", "classes2.dex", ....
+     *
+     * @param context the application context
+     * @return all the classes name
+     * @throws PackageManager.NameNotFoundException
+     * @throws IOException
+     */
+    public static List<String> getAllClasses(Context context) throws PackageManager.NameNotFoundException, IOException {
+        List<String> classNames = new ArrayList<String>();
+        for (String path : getSourcePaths(context)) {
+            try {
+                DexFile dexfile = null;
+                if (path.endsWith(EXTRACTED_SUFFIX)) {
+                    //NOT use new DexFile(path), because it will throw "permission error in /data/dalvik-cache"
+                    dexfile = DexFile.loadDex(path, path + ".tmp", 0);
+                } else {
+                    dexfile = new DexFile(path);
+                }
+                Enumeration<String> dexEntries = dexfile.entries();
+                while (dexEntries.hasMoreElements()) {
+                    classNames.add(dexEntries.nextElement());
+                }
+            } catch (IOException e) {
+                throw new IOException("Error at loading dex file '" +
+                        path + "'");
+            }
+        }
+        return classNames;
+    }
+}
\ No newline at end of file
diff --git a/library/src/main/java/com/orm/util/ReflectionUtil.java b/library/src/main/java/com/orm/util/ReflectionUtil.java
index a740b42d..e6e2dd38 100644
--- a/library/src/main/java/com/orm/util/ReflectionUtil.java
+++ b/library/src/main/java/com/orm/util/ReflectionUtil.java
@@ -289,15 +289,11 @@ private static Class getDomainClass(String className, Context context) {
 
     private static List<String> getAllClasses(Context context) throws PackageManager.NameNotFoundException, IOException {
         String packageName = ManifestHelper.getDomainPackageName(context);
-        String path = getSourcePath(context);
         List<String> classNames = new ArrayList<String>();
-        DexFile dexfile = null;
         try {
-            dexfile = new DexFile(path);
-            Enumeration<String> dexEntries = dexfile.entries();
-            while (dexEntries.hasMoreElements()) {
-                String className = dexEntries.nextElement();
-                if (className.startsWith(packageName)) classNames.add(className);
+            List<String> allClasses = MultiDexHelper.getAllClasses(context);
+            for (String classString : allClasses) {
+                if (classString.startsWith(packageName)) classNames.add(classString);
             }
         } catch (NullPointerException e) {
             ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
@@ -316,7 +312,7 @@ private static List<String> getAllClasses(Context context) throws PackageManager
                 }
             }
         } finally {
-            if (null != dexfile) dexfile.close();
+//            if (null != dexfile) dexfile.close();
         }
         return classNames;
     }