Based on the nonlinear feedback approach for realizing any continuous time scalar(hyper)chaotic signal synchronization control,we have designed an adaptive feedback controller for controlling the scalar output signal of a smooth(hyper)chaotic system to synchronize with any continuous time scalar(hyper)chaotic signal under some assumptions.The result,which is rigorously proved by means of stability theory,not only can adaptively estimate the control parameter,but also has some robustness against parameter variations and external disturbances.An application to the synchronization of two(hyper)chaotic systems is given.