This paper investigates the region reaching control problem of networked multi-robot systems modeled by Lagrangian dynamics. The primary objective is to develop the concept of region reaching control for single robot for the study of networked multi-robot systems under directed topology graph. The distributed region reaching control protocols for such networked multi-robot systems are first proposed, and then some simple yet generic criteria on the convergence for such protocols are established. It is shown that networked multi-robot systems can always reach the desired region under the proposed region reaching control protocols if the directed network topology graph has a directed spanning tree. Finally, simulation results are presented to illustrate the effectiveness of the theoretical analysis.