Security is a prime concern in our day-today life. Everyone wants to be as much secure as possible. An access control for doors forms a vital link in a security chain. The Microcontroller based Home Security System can be adopted at Home it has various type of Sensors. In our Project we have magnetic sensors, Wire Loop sensors, Fire sensors. The system is fully controlled by the 8 bit microcontroller AT89C52 which has a 8Kbytes of ROM for the program memory. The Microcontroller will continuously monitors all the Sensors and if it found any security problem then the Microcontroller will switch on the Alarm until the Reset button was Pressed.