An active sliding mode control is designed to anti-synchronize different chaotic systems. The closed loop error dynamics depends on the linear part of the response systems and parameters of the controller. Therefore, the anti-synchronization rate can be adjusted through these parameters. Analysis of the stability for the proposed method is done based on the Lyapunov stability theorem. Finally, numerical results are presented for the Lorenz, Chen and Lü systems. This method may realize the anti-synchronization quickly, and the robust stability is good.