A method for constituting identification code utilized in a wireless human input device includes the following steps. Step A is to save a predetermined identification code in a non-electrical memory of a wireless human receiving device. Step B is that the wireless human transmitting device sends a packet contained an identification code with the same value as the predetermined identification code to the wireless human receiving device during the wireless human transmitting device being first time set up. The identification code is automatically generated by micro controller of the wireless human transmitting device. Step C is that the wireless human receiving device receives the packet in step B. Step D is that the computer detects if the wireless human receiving device in step C can receive normally via executing program codes and the computer reads the memory of the wireless human receiving device via executing the program codes in case of normal receiving being detected, and then the computer compares the predetermined identification code to the read data and outputs a message of the wireless human input device being normally operated if a result is true after comparison.