In this proposed system the idea is to build a system that could raise alarm when it detects smoke in its surrounding. As soon as the smoke detector detects smoke, the low voltage signal activates the relay on the smoke detector causing it to emit a tone that alerts the residents. Smoke Detectors are particularly concerned with local residents to avoid any accident due to fire, short circuit .Improper precautions during fire or any incident related to smoke may lead to loss of life or serious harm to properties.The proposed system may allow the common people to attach a smoke detecting system at low price . The proposed system will allow people to get alarmed of any smoke detection at there house, offices etc. The existing smoke detecting system basically uses ionization type of alarm which has some radioactive material between two electrically charged plates which are more costlier than the proposed system. In the proposed system we have used MQ2 sensors. In MQ2 sensors the greater the gas concentration is the greater the output is.Similarly the lower the gas concentration the lower the output. We have also used the Arduino Leonardo which contains both a physical programmable circuit board (often referred to as a microcontroller) and a piece of software, or IDE (Integrated Development Environment) that runs on your computer.By using this u could write the computer code and upload it into Physical circuit.