A method for optimizing an integrated circuit layout design includes the following steps. A first integrated circuit layout design including a metal line feature having several metal lines and a second integrated circuit layout design including a hole feature having several holes are obtained. A line-end hole feature of the hole feature is selected by piecing the metal line feature with the hole feature. The line-end hole feature is classified into a single hole feature and a redundant hole feature by spacings between the adjacent holes by a computer system.