This paper deals with formation control of mobile robots based on interconnected positive systems with SISO subsystems where each robot has a nonlinear dynamics of a MIMO subsystem. To linearize the dynamics, this paper introduces a virtual vehicle of the robot. Then a feedback linearization and a local feedback law transform each dynamics of the virtual vehicle into two SISO positive and stable linear systems. Consequently, the dynamics of the virtual vehicles satisfy the properties of the interconnected positive systems. Experimental results as well as numerical examples including leader-follower formation control for the mobile robots are illustrated.