diff --git a/libs/P_C.py b/libs/P_C.py
index 9e9402e..f55e1cb 100644
--- a/libs/P_C.py
+++ b/libs/P_C.py
@@ -75,5 +75,8 @@ def G_C(M, m, R, G): #stand for gravity calculation
     G : Gravitational constant
     M & m & R format: docs.basic_config:basic_number
     """
-    pass
+    g = libs.config.basic_number()
+    A = S_N_M(M, m, G)
+    B = S_N_D(A, S_N_M(R, R))
+    return B
 
diff --git a/libs/__init__.py b/libs/__init__.py
index c976dad..6498c8e 100644
--- a/libs/__init__.py
+++ b/libs/__init__.py
@@ -11,5 +11,6 @@ import libs.main
 import libs.tools
 import libs.loads
 import libs.setup
+import libs.config
 import libs.delivery
 import libs.render_thread
diff --git a/libs/config.py b/libs/config.py
new file mode 100644
index 0000000..d611dde
--- /dev/null
+++ b/libs/config.py
@@ -0,0 +1,12 @@
+"""
+writen by shenjackyuanjie
+mail: 3695888@qq.com
+"""
+
+import libs
+
+def basic_number(Int=0, Float=1, unit1=[], unit2=[]):
+    return [Int, Float, unit1, unit2]
+
+def basic_force():
+    return [basic_number(unit1=["N"]), basic_number(unit1=["N"])]