This paper presents a formation control method for multiple autonomous underwater vehicles (AUVs) using region control concept. The desired formation is specified by the shape of the chosen region where all robots are required to stay inside. To avoid collision among the members of the group, minimum distance between robots is specified. Using this region control method, we shall show that a simple PD plus gravity compensation controller works on a complex system consisting of a group of multiple AUVs moving in a formation. Lyapunov-like functions are proposed for the stability analysis. Simulation studies on AUVs with 6 degrees of freedom are presented to demonstrate the effectiveness of the proposed controller.