Alarming and Decision Support System Ranjana Pushkarna Student Symbiosis Institute of Geoinformatics, India Email: r.pushkarna@gmail.com Can you think of a system that is intelligent enough to sense any kind of fire or temperature rise at your home and not only that but informs you and the concerned personnel about this incidence of fire , providing them other information like your address and the optimum route to reach that very place? This paper presents a project that describes the same type of intelligent system. This paper integrates two parts, alarming and the GIS part as a decision support system. The first part considers the sensors, microcontrollers, and cables and the most important the mobile instrument. This is basically a ‘microcontroller based monitoring system using SMS on mobile’. This works as follows: Sensors sense any kind of fire and send signals to the microcontroller. Microcontroller already programmed then sends instructions to the mobile instrument to send SMS. The instrument sends the already fed SMS to the saved numbers. The second part of the project is to provide the optimum route to the fire station personnel to reach the place as soon as possible and that is done with help of GIS as follows: One GIS wing is established in the city where that SMS is sent. These people match the address from the digitized map they have got of the whole area.Then they check for the optimum route to this place and provide the information to the concerned personnel in the fire department. Hence this system helps in taking rapid action in case of accidents like fire.