This paper explored the cognitive recognition on the complexity of shape contour. Fifty combinations composed of different shape features served as the stimuli to the subjects in this experiment. The primary findings in this study were: 1. The increment of the complex level was positively related to the increase of shape elements contained in a testing figure. 2. In terms of the cognition of shape symmetric, symmetric shapes were less complex than asymmetric shapes. 3. The complex level rose positively corresponding to the amount of shape operations. 4. Regression analysis was applied to investigate the relationship between shape features and shape complexities. The result showed that twelve shape features have different degrees of effects on the complexity of shape cognition.