The present invention provides a method of checking and correcting a mask pattern. The method includes inputting a mask pattern, wherein the mask pattern includes at least a segment; inputting a process rule; selecting an edge, which fits in with an orientation model, as a target edge, wherein two ends of the target edge are an ahead direction and a behind direction, and the ahead direction and the behind direction each further comprise at least a checking point; identifying an interacting edge from the mask pattern along the checking directions; performing a process rule check to provide a correcting value; performing a first correction to provide a first bias to the target edge; and performing a second correction to provide a second bias to the interacting edge, wherein a sum of the first bias and the second bias equals the correcting value.