This paper concerns with the problem of synchronization of complex dynamical networks (CDNs) with discontinuous coupling signals which are kept constant during the sampling period and are allowed to change only at the sampling instant. Based on the time-dependent Lyapunov functional approach, convex combination technique, and multiple-integral method, a sampling interval- dependent criterion is derived for synchronization of CDNs with discontinuous coupling signals. Numerical examples are given to demonstrate the effectiveness of proposed method and the relation between conservatism of results and triple integral method.