Abstract: The present invention provides a method utilizing dummy patterns to fabricate active region for stabilizing lithographic process. An original pattern layer of active region is first provided, and an attached diffusion layer of dummy patterns is then matched. Logic operations are used to combine the original pattern layer of active region and the attached diffusion layer of dummy patterns together to fill the attached diffusion layer of dummy patterns in more spacious region of the original pattern layer of active region for increasing the pattern density of active region for mask fabrication, hence acquiring a photo mask meeting the requirement of logic device product and applying to logic devices having different pattern densities of active region. Difference of density between products can thus be reduced. The present invention utilizes dummy patterns to simplify and stabilize lithographic process. Simultaneously, lens heating effect can also be reduced.