An optical proximity correction (OPC) process is provided. The method comprising receiving a first pattern corresponding to a first structure of a semiconductor structure, and a second pattern corresponding to a second structure of said semiconductor structure. Next, a first OPC process is performed for the first pattern to obtain a revised first pattern, wherein the revised first pattern has a first shift regarding to the first pattern. A second OPC process is performed for the second pattern to obtain a revised second pattern, wherein the second OPC process comprises moving the second pattern according to the first shift.