When the crime is increasing, particularly in the case of motor vehicle theft. The solution is usually done by the motor vehicle user just double lock on they vehicle. thieves can make duplicate keys of vehicles so that the thief can be relaxed to take they vehicle. Technological developments in this time, mobile phone technology has been transformed into a multifunctional device. By utilizing SMS (Short Message Service) can control the security system of motor vehicles using Microcontroller AT-Mega 328,as well as the GPS module SIMCOM SIM908 to be able to know the location of the vehicle is located. With increasingly sophisticated technology now. expected crime, particularly theft of the vehicle can be reduced. With the motor security system using GPS-based SMS media can provide more security to the owner of the motor vehicle, because the owner can be know where their vehicle if something happens theft.