An impulsive control scheme is proposed to investigate the tracking synchronization of ring and inline networked Lagrangian systems. Given a time-varying target trajectory, some algebraic synchronization criteria are derived to make the networked Lagrangian systems synchronize to the target trajectory. A distinctive feature of the proposed work is that the impulsive control scheme is used to investigate the highly nonlinear Lagrangian systems. By the impulsive control, each agent described by the Lagrangian system instantaneously interacts with its neighbors only at some discrete moments. Furthermore, the proposed control strategy requires only local coupling feedback for global convergence. As a direct application of the obtained theoretical results, the tracking synchronization of multiple 3-DOF mobile robots is discussed in detail and simulated. Simulation results verify the effectiveness of the proposed control strategy.