diff --git a/MdePkg/Library/DxeIoLibEsal/IoLib.c b/MdePkg/Library/DxeIoLibEsal/IoLib.c
index 7bc6ff1b61..81b28ecdd9 100644
--- a/MdePkg/Library/DxeIoLibEsal/IoLib.c
+++ b/MdePkg/Library/DxeIoLibEsal/IoLib.c
@@ -38,6 +38,8 @@ IoReadWorker (
   SAL_RETURN_REGS  ReturnReg;
   UINT64           Data;
 
+  Data = 0;
+
   ReturnReg = EsalCall (
                 EFI_EXTENDED_SAL_BASE_IO_SERVICES_PROTOCOL_GUID_LO,
                 EFI_EXTENDED_SAL_BASE_IO_SERVICES_PROTOCOL_GUID_HI,
@@ -119,6 +121,8 @@ MmioReadWorker (
   SAL_RETURN_REGS  ReturnReg;
   UINT64           Data;
 
+  Data = 0;
+
   ReturnReg = EsalCall (
                 EFI_EXTENDED_SAL_BASE_IO_SERVICES_PROTOCOL_GUID_LO,
                 EFI_EXTENDED_SAL_BASE_IO_SERVICES_PROTOCOL_GUID_HI,
diff --git a/MdePkg/Library/DxeSalLibEsal/DxeSalLibEsal.c b/MdePkg/Library/DxeSalLibEsal/DxeSalLibEsal.c
index b013146eb2..8d1dd9ae15 100644
--- a/MdePkg/Library/DxeSalLibEsal/DxeSalLibEsal.c
+++ b/MdePkg/Library/DxeSalLibEsal/DxeSalLibEsal.c
@@ -59,6 +59,14 @@ SalCall (
   )
 {
   SAL_RETURN_REGS Regs;
+  
+  //
+  // Initial all members in this structure.
+  //
+  Regs.r9     = 0;
+  Regs.r10    = 0;
+  Regs.r11    = 0;
+  Regs.Status = EFI_SAL_INVALID_ARGUMENT;
 
   switch (Index) {
   case EFI_SAL_SET_VECTORS:
@@ -272,7 +280,6 @@ SalCall (
     break;
 
   default:
-    Regs.Status = EFI_SAL_INVALID_ARGUMENT;
     return Regs;
     break;
   }