assest is a very important capital for each individual or corporate that insists a safe security mechanism and is able to give information for the user in the real time and the existing system condition. there is a lot of mechanism to do to get a system to reassure the asset, begin from manual system by put the securior until the alarm system that will give the signal when the undersirable condition happen. nevertheless, our necessity increasingly and assert a system that could supply the real time information about the existing system condition so the user can know about what happen in that system. therfore, in this graduating paper the writer design a security system that can supply the real time information to the use by name "prototype design of the room security system based on short message services (SMS). from the result of this research, we can conclude that by implementing this room security system based on short message services (SMS will make the controlling to the existing system aesier for the user, because the user can get the real time information in message that will accepted by the user's hand phone in a short message