Abstract: The stabilization problem for a class of networked control systems with aperiodic sampling and stochastic packet dropouts was studied. Other than the traditional view that a time delay was often a negative factor of system stability, the positive effect was considered and a novel active timedelay control method was proposed to stabilize the systems. To analyze the positive effects of the time delay control and to obtain some less conservative conclusions, the aperiodic sampleddata system with stochastic packet dropouts was firstly modeled as a stochastic impulsive switched system with a fixed switching law. Then a new separation lemma was presented in a mean square sense to analyze the stability of the stochastic impulsive switched system. Based on the loopfunctional method and the proposed separation lemma, the mean square stability criterion for the stochastic impulsive switched system was obtained in terms of linear matrix inequalities. Furthermore, the refined mean square stability criterion was given with an interval segmentation technique. Finally, a classical numerical example illustrates the validity of the obtained stability criteria and the advantages of the proposed method.