The aim of this paper to spread the engineering knowledge and also find out vehicles, which are stolen. This paper considers an overview of Car security system using GSM technology, software development and its applications. The whole circuit is divided into two main parts, the first part deals with the algorithm/coding and the second part deals with the hardware. Later part of report covers the methodology and working of project. Security system is one from the fast growing engineering technologies. It has a number of applications in different areas and provides potential benefits. Although we now associate the word to an electronic machine, it still stays true to the meaning of word.

Keywords : GSM, GPRS, Aurdino, Sim Holder, Antenna