A photomask and method for fabricating an integrated circuit is provided. The photomask includes a plurality of main features, enclosed in at least one first region and at least one second region, wherein the first region comprises single the main feature and the second region comprises multiple the main features; and a plurality of assistant features disposed between the first region and the second region, or between the second regions. The photomask enhances the accuracy of the critical dimension and facilitate fabricating an integrated circuit.