Over the last few years the “Wireless Sensor Network” technology has become more popular and more used, because it has so many applications which can be implemented with wide range of different sensors. Here we are trying to make a system on the basis of this technology. “Detection and tracking of target through its acoustic sound” is our basic aim. It is a system which comprises of different modules such as acoustic sensor board, microcontroller & radio board, programming and interfacing board, Pc serial interfacing board of Mote-kit Mica2 by Crossbow. Whenever any object moves it creates some sound, called acoustic sound. This acoustic sound has several frequencies components. This system collects the acoustic sound through its onboard acoustic sensor. This sensor senses the sound in the range of 3 to 4 meters. This collected acoustic signal is in analog form which in turn is converted into digital one and then can be processed by microcontroller which is also onboard. This processed data can be sent to the computer via RS232 port, and system can be controlled by computer (using its software). By providing this data on the internet we can access it from anywhere in the world. We can also locate the position of the target in network.