A novel active backstepping control method is presented for synchronizing two identical Rossler hyperchaotic systems with each other, and extended to achieve the generalized synchronization of the Chua chaotic system with the Rossler hyperchaotic system. It is a systematic design approach and consists of a recursive procedure interlacing the choice of a Lyapunov function with the design of active control. In particular, this technique gives flexibility in constructing a control law. Numerical experiments verify the feasibility and effectiveness of the proposed control technique.