This paper attempts to give a perspective on decentralized formation control of multiple car-like mobile robots using local information and formation changes in a dynamic environment having several obstacles. In addition, for every mobile robot, it takes physical dimensions, mass, moment of inertia, movement constraints, and saturation of actuators into account. This study makes use of Input/Output Feedback Linearization Method to control each robot. Hence, hierarchical leader-follower based algorithm is employed to control the group formation. To avoid collision between robots and obstacles, and of robots with each other, local arti cial potential elds are addressed. The group can change formation with respect to obstacles in the environment. Finally, simulation results of seven individual robots formation are presented to show the performance of the proposed control system.