In the present paper, we evaluate the inter-cell interference of AS-CDMA systems. First, the cross-correlation property of AS-CDMA systems is examined by theoretical study in order to clarify the fundamental feature of the inter-cell interference. The result shows that the influence of one interference terminal in each adjacent cell is dominant regardless of whether approximate synchronization is maintained. Next, the ratio of interference signal power and desired signal power is evaluated by computer simulation. The simulation result shows that total interference power does not increase even when approximate synchronization is not maintained.