In wireless sensor networks (WSNs), sensor deployment is an important issue which intends to deploy sensors in a given monitoring region in a way of low hardware cost and high coverage quality. In literature, some robot deployment algorithms have been proposed. Their performances are mainly determined by the obstacle-resistance capability which refers to how well the robot can overcome the Dead-End problem and deploy minimal number of sensors for achieving full coverage even though the environment contains multiple obstacles. Moreover, most of the existing robot deployment mechanisms consider only single robot for executing the deployment task. This thesis presents a multi-robot cooperative deployment algorithm for multiple robots to cooperate with each other aiming at deploying minimal number of sensors while achieving the full coverage purpose even though the given monitoring region contains unknown obstacles.