an anti - theft and two - way communication apparatus for vehicles and particularly an apparatus capable of examining incoming phone numbers to prevent vehicle theft . the apparatus mainly consists of a communication module and a vehicle anti - theft module . a fixed line or wireless telephone with a preset phone number may be dialed to the communication module to set or release the vehicle anti - theft module thereby to greatly reduce vehicle theft . the signals of the incoming phone number are generated by communication systems thus cannot be forged or replicated illegitimately , and can prevent replication by burglars during the remote control operation .