A user certification method of mobile communication system includes confirming public key of network end in network center at system initialization course and disclosing relevant parameter of network center to user then confirming public key at user end by selecting random number at user end, setting up user status ID by network center and sending it to user end for using it to carry out status verification, setting up relevant databank by network center and calculating out user signature being sent to network center, querying public key of user end in databank by network center according to user signature to verify whether user is legal user or not. |