diff --git a/Fortran/FUNC_sign.f90 b/Fortran/FUNC_sign.f90
new file mode 100644
index 0000000..c499f31
--- /dev/null
+++ b/Fortran/FUNC_sign.f90
@@ -0,0 +1,19 @@
+
+    !·ûºÅº¯Êý
+    real*8 function FUNC_sign(A)
+    implicit none
+    
+    real*8 :: A
+    if(isnan(A)) then
+        FUNC_sign = A
+    elseif(A>0) then
+        FUNC_sign = 1.0
+    elseif(A<0) then
+        FUNC_sign = -1.0
+    elseif(A==0) then
+        FUNC_sign = 0.0
+    end if
+    
+    end function
+    
+    
\ No newline at end of file