Abstract: A variable structure control scheme was proposed for the networked control systems with the networks existing between sensors and controllers. However, the full state of plant can not be directly measurable, so an observer-based controller was established. If the considered delay is smaller than the maximum admissible delay, the observer gain matrix can be calculated by solving a linear matrix inequality that guarantees the error system to be exponential asymptotically stable. The controller gain matrix can be determined by using pole placement or optimal control method and the main results can guarantee the sliding mode to be exponential asymptotically stable. Using the exponential reaching index can adjust the corresponding parameters to weaken the jittering so that the required performance of systems is ensured. A simulation example was given to illustrate the feasibility and effectiveness of the proposed method.