Dot shape is one of the main factors influencing image reproducing quality. Under certain experimental condition, with the testing images of standard color image data N1～N8, dot shapes of square, square-and-round, round and ellipse were adopted in output processing. Image quality elements of tonal level, sharpness, color and gray balance were evaluated subjectively and grading results were also counted and analyzed. The experimental results showed that round is the best dot shape for highlight, sharpness, and color reproduction; shape of ellipse, square-and-round are optimum for middle and shadow tone images.