In a photoresist composition for a semiconductor manufacturing process and a method of forming a photoresist pattern using the photoresist composition, the photoresist composition includes an organic dispersing agent for dispersing acid (H+). The photoresist film may have enough spaces among photosensitive polymers so that acid may be dispersed sufficiently in an exposure process. Thus, a photoresist pattern may be easily formed in a defocus region. Defects in a semiconductor device may be reduced and a productivity of the semiconductor manufacturing process may be enhanced.