diff --git a/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c b/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c
index e59a9de3d1..4b86f50762 100644
--- a/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c
+++ b/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c
@@ -1,7 +1,7 @@
 /** @file
   UEFI Decompress Library implementation refer to UEFI specification.
 
-  Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
   Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
@@ -68,7 +68,7 @@ FillBuf (
   }
 
   //
-  // Caculate additional bit count read to update mBitCount
+  // Calculate additional bit count read to update mBitCount
   //
   Sd->mBitCount = (UINT16) (Sd->mBitCount - NumOfBits);
   
@@ -777,7 +777,7 @@ UefiDecompress (
   Sd->mSrcBase  = (UINT8 *)Src;
   Sd->mDstBase  = Dst;
   //
-  // CompSize and OrigSize are caculated in bytes
+  // CompSize and OrigSize are calculated in bytes
   //
   Sd->mCompSize = CompSize;
   Sd->mOrigSize = OrigSize;
diff --git a/MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c b/MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c
index 49d7a57a02..ab27ac6583 100644
--- a/MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c
+++ b/MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c
@@ -11,7 +11,7 @@
   In addition, allocation for the Reserved memory types are not supported and 
   will always return NULL.
 
-  Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials                          
   are licensed and made available under the terms and conditions of the BSD License         
   which accompanies this distribution.  The full text of the license may be found at        
@@ -320,7 +320,7 @@ InternalAllocateAlignedPages (
   }
   if (Alignment > EFI_PAGE_SIZE) {
     //
-    // Caculate the total number of pages since alignment is larger than page size.
+    // Calculate the total number of pages since alignment is larger than page size.
     //
     AlignmentMask  = Alignment - 1;
     RealPages      = Pages + EFI_SIZE_TO_PAGES (Alignment);
diff --git a/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c b/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c
index f1eaccc8dc..3da5e21113 100644
--- a/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c
+++ b/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c
@@ -2,7 +2,7 @@
   Support routines for memory allocation routines based 
   on boot services for Dxe phase drivers.
 
-  Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials                          
   are licensed and made available under the terms and conditions of the BSD License         
   which accompanies this distribution.  The full text of the license may be found at        
@@ -194,7 +194,7 @@ InternalAllocateAlignedPages (
   }
   if (Alignment > EFI_PAGE_SIZE) {
     //
-    // Caculate the total number of pages since alignment is larger than page size.
+    // Calculate the total number of pages since alignment is larger than page size.
     //
     AlignmentMask  = Alignment - 1;
     RealPages      = Pages + EFI_SIZE_TO_PAGES (Alignment);