diff --git a/darpanx/darpanx_mlcal.py b/darpanx/darpanx_mlcal.py
index fb7cec7..0bbe5f0 100644
--- a/darpanx/darpanx_mlcal.py
+++ b/darpanx/darpanx_mlcal.py
@@ -40,6 +40,10 @@ def __init__(self,NK_dir=None, LayerMaterial=None, Repetition=None, NumStack=Non
         try:
             NumCore=int(NumCore)
             if NumCore > 0:
+                cpu=mulp.cpu_count()
+                if NumCore > cpu:
+                    print("%% DarpanX_message: NumCore is exciding the maximum value. Set NumCore = "+str(cpu))
+                    NumCore=cpu
                 print("%% DarpanX_status: Parallel processing is using with no.cores = "+str(NumCore))
                 self.NumCore=NumCore
             else: print("%% DarpanX_Error: < NumCore > should be an integer, like 1,2,3...")
diff --git a/darpanx/darpanx_utilities.py b/darpanx/darpanx_utilities.py
index f8241e9..1c365b4 100644
--- a/darpanx/darpanx_utilities.py
+++ b/darpanx/darpanx_utilities.py
@@ -24,6 +24,7 @@
 from os import path
 from darpanx.get_dir import*
 import sys
+import multiprocessing as mlp
 '''
 #-----------------------------------------------
 Perpose:
@@ -536,6 +537,10 @@ def read_infile(UserInFile):
         NumCore=l2[l1.index('NumCore')][1:-1]
         NumCore=int(NumCore)
         if NumCore > 0:
+            cpu=mlp.cpu_count()
+            if NumCore > cpu:
+                print("%% DarpanX_message: NumCore is exciding the maximum value. Set NumCore = "+str(cpu))
+                NumCore=cpu
             print("%% DarpanX_message: Parallel processing is using with no.cores = "+str(NumCore))
         else: print("%% DarpanX_Error: < NumCore > should be an integer, like 1,2,3...")
     except:NumCore=None