We deal with synchronization of a class of discrete-time dynamical networks. First, a novel model for discrete-time dynamical networks with impulsive couplings between nodes is proposed. Second, both global and local stability of synchronization manifold is investigated using the multiple Lyapunov function method and some inequality techniques. As a result, several synchronization criteria are obtained. Third, two illustrative examples are given to validate the effectiveness of the proposed synchronization criteria. Analysis on the synchronization regions of the discrete-time dynamical network with metapopulation dynamics is further made, which reveals such a finding that either a relatively large coupling strength or a short impulsive interval is not necessarily beneficial to synchronization of the discrete-time dynamical network.