diff --git a/MdePkg/Include/IndustryStandard/UefiTcgPlatform.h b/MdePkg/Include/IndustryStandard/UefiTcgPlatform.h
index 61bd4e4667..aaee5d6c88 100644
--- a/MdePkg/Include/IndustryStandard/UefiTcgPlatform.h
+++ b/MdePkg/Include/IndustryStandard/UefiTcgPlatform.h
@@ -451,6 +451,7 @@ typedef struct tdTCG_PCClientTaggedEvent {
 
 #define TCG_Sp800_155_PlatformId_Event_SIGNATURE   "SP800-155 Event"
 #define TCG_Sp800_155_PlatformId_Event2_SIGNATURE  "SP800-155 Event2"
+#define TCG_Sp800_155_PlatformId_Event3_SIGNATURE  "SP800-155 Event3"
 
 typedef struct tdTCG_Sp800_155_PlatformId_Event2 {
   UINT8       Signature[16];
@@ -478,9 +479,44 @@ typedef struct tdTCG_Sp800_155_PlatformId_Event2 {
   // UINT8               FirmwareManufacturerStr[FirmwareManufacturerStrSize];
   // UINT32              FirmwareManufacturerId;
   // UINT8               FirmwareVersion;
-  // UINT8               FirmwareVersion[FirmwareVersionSize]];
+  // UINT8               FirmwareVersion[FirmwareVersionSize];
 } TCG_Sp800_155_PlatformId_Event2;
 
+typedef struct tdTCG_Sp800_155_PlatformId_Event3 {
+  UINT8       Signature[16];
+  //
+  // Where Vendor ID is an integer defined
+  // at http://www.iana.org/assignments/enterprisenumbers
+  //
+  UINT32      VendorId;
+  //
+  // 16-byte identifier of a given platform's static configuration of code
+  //
+  EFI_GUID    ReferenceManifestGuid;
+  // UINT8               PlatformManufacturerStrSize;
+  // UINT8               PlatformManufacturerStr[PlatformManufacturerStrSize];
+  // UINT8               PlatformModelSize;
+  // UINT8               PlatformModel[PlatformModelSize];
+  // UINT8               PlatformVersionSize;
+  // UINT8               PlatformVersion[PlatformVersionSize];
+  // UINT8               PlatformModelSize;
+  // UINT8               PlatformModel[PlatformModelSize];
+  // UINT8               FirmwareManufacturerStrSize;
+  // UINT8               FirmwareManufacturerStr[FirmwareManufacturerStrSize];
+  // UINT32              FirmwareManufacturerId;
+  // UINT8               FirmwareVersion;
+  // UINT8               FirmwareVersion[FirmwareVersionSize];
+  //
+  // Below structure is newly added in TCG_Sp800_155_PlatformId_Event3
+  //
+  // UINT32              RimLocatorType;
+  // UINT32              RimLocatorLength;
+  // UINT8               RimLocator[RimLocatorLength];
+  // UINT32              PlatformCertLocatorType;
+  // UINT32              PlatformCertLocatorLength;
+  // UINT8               PlatformCertLocator[PlatformCertLocatorLength];
+} TCG_Sp800_155_PlatformId_Event3;
+
 #define TCG_EfiStartupLocalityEvent_SIGNATURE  "StartupLocality"
 
 //