Index: Source/Python/Ecc/Check.py
===================================================================
--- Source/Python/Ecc/Check.py	(revision 17671)
+++ Source/Python/Ecc/Check.py	(working copy)
@@ -561,6 +561,7 @@
         self.MetaDataFileCheckLibraryInstanceDependent()
         self.MetaDataFileCheckLibraryInstanceOrder()
         self.MetaDataFileCheckLibraryNoUse()
+        self.MetaDataFileCheckLibraryDefinedInDec()
         self.MetaDataFileCheckBinaryInfInFdf()
         self.MetaDataFileCheckPcdDuplicate()
         self.MetaDataFileCheckPcdFlash()
@@ -692,7 +693,24 @@
                     for FilePath in FilePathList:
                         if not EccGlobalData.gException.IsException(ERROR_META_DATA_FILE_CHECK_LIBRARY_NAME_DUPLICATE, Record[1]):
                             EccGlobalData.gDb.TblReport.Insert(ERROR_META_DATA_FILE_CHECK_LIBRARY_NAME_DUPLICATE, OtherMsg="The Library Class [%s] is duplicated in '%s' line %s and line %s." % (Record[1], FilePath, Record[3], Record[4]), BelongsToTable='Dsc', BelongsToItem=Record[0])
-                                                
+    
+    # Check the header file in Include\Library directory whether be defined in the package DEC file.
+    def MetaDataFileCheckLibraryDefinedInDec(self):
+        if EccGlobalData.gConfig.MetaDataFileCheckLibraryDefinedInDec == '1' or EccGlobalData.gConfig.MetaDataFileCheckAll == '1' or EccGlobalData.gConfig.CheckAll == '1':
+            EdkLogger.quiet("Checking for library instance whether be defined in the package dec file ...")
+            SqlCommand = """
+                    select A.Value1, A.StartLine, A.ID, B.Value1 from Inf as A left join Dec as B
+                    on A.Model = B.Model and A.Value1 = B.Value1 where A.Model=%s
+                    """ % MODEL_EFI_LIBRARY_CLASS
+            RecordSet = EccGlobalData.gDb.TblDsc.Exec(SqlCommand)
+            for Record in RecordSet:
+                LibraryInInf, Line, ID, LibraryDec = Record
+                if not LibraryDec:
+                    if not EccGlobalData.gException.IsException(ERROR_META_DATA_FILE_CHECK_LIBRARY_NOT_DEFINED, LibraryInInf):
+                        EccGlobalData.gDb.TblReport.Insert(ERROR_META_DATA_FILE_CHECK_LIBRARY_NOT_DEFINED, \
+                                            OtherMsg="The Library Class [%s] in %s line is not defined in the associated package file." % (LibraryInInf, Line), 
+                                            BelongsToTable='Inf', BelongsToItem=ID)
+    
     # Check whether an Inf file is specified in the FDF file, but not in the Dsc file, then the Inf file must be for a Binary module only
     def MetaDataFileCheckBinaryInfInFdf(self):
         if EccGlobalData.gConfig.MetaDataFileCheckBinaryInfInFdf == '1' or EccGlobalData.gConfig.MetaDataFileCheckAll == '1' or EccGlobalData.gConfig.CheckAll == '1':
Index: Source/Python/Ecc/config.ini
===================================================================
--- Source/Python/Ecc/config.ini	(revision 17671)
+++ Source/Python/Ecc/config.ini	(working copy)
@@ -230,6 +230,8 @@
 MetaDataFileCheckLibraryInstanceOrder = 1
 # Check whether the unnecessary inclusion of library classes in the INF file
 MetaDataFileCheckLibraryNoUse = 1
+# Check the header file in Include\Library directory whether be defined in the package DEC file.
+MetaDataFileCheckLibraryDefinedInDec = 1
 # Check whether an INF file is specified in the FDF file, but not in the DSC file, then the INF file must be for a Binary module only
 MetaDataFileCheckBinaryInfInFdf = 1
 # Not to report error and warning related OS include file such as "windows.h" and "stdio.h".
Index: Source/Python/Ecc/Configuration.py
===================================================================
--- Source/Python/Ecc/Configuration.py	(revision 17671)
+++ Source/Python/Ecc/Configuration.py	(working copy)
@@ -220,6 +220,8 @@
         self.MetaDataFileCheckLibraryInstanceOrder = 1
         # Check whether the unnecessary inclusion of library classes in the INF file
         self.MetaDataFileCheckLibraryNoUse = 1
+        # Check the header file in Include\Library directory whether be defined in the package DEC file.
+        self.MetaDataFileCheckLibraryDefinedInDec = 1
         # Check whether an INF file is specified in the FDF file, but not in the DSC file, then the INF file must be for a Binary module only
         self.MetaDataFileCheckBinaryInfInFdf = 1
         # Not to report error and warning related OS include file such as "windows.h" and "stdio.h"
Index: Source/Python/Ecc/EccToolError.py
===================================================================
--- Source/Python/Ecc/EccToolError.py	(revision 17671)
+++ Source/Python/Ecc/EccToolError.py	(working copy)
@@ -100,6 +100,7 @@
 ERROR_META_DATA_FILE_CHECK_FORMAT_PROTOCOL = 10019
 ERROR_META_DATA_FILE_CHECK_FORMAT_PPI = 10020
 ERROR_META_DATA_FILE_CHECK_FORMAT_PCD = 10021
+ERROR_META_DATA_FILE_CHECK_LIBRARY_NOT_DEFINED = 10022
 
 ERROR_SPELLING_CHECK_ALL = 11000
 
@@ -193,6 +194,7 @@
     ERROR_META_DATA_FILE_CHECK_FORMAT_PROTOCOL : "Wrong Protocol Format used in Module file",
     ERROR_META_DATA_FILE_CHECK_FORMAT_PPI : "Wrong Ppi Format used in Module file",
     ERROR_META_DATA_FILE_CHECK_FORMAT_PCD : "Wrong Pcd Format used in Module file",
+    ERROR_META_DATA_FILE_CHECK_LIBRARY_NOT_DEFINED : "Not defined LibraryClass used in the Module file.",
     ERROR_SPELLING_CHECK_ALL : "",
     }