For a sequence of bounded linear operators { A n } n = 0 ∞ on a Banach space X, we investigate the characterization of exponential dichotomy of the difference equations v n + 1 = A n v n . We characterize the exponential dichotomy of difference equations in terms of the existence of solutions to the equations v n + 1 = A n v n + f n in l p spaces ( 1 ≤ p < ∞ ) . Then we apply the results to study the robustness of exponential dichotomy of difference equations.