This study aims to examine the developmental changes in young children's perception. A matching completion task consisting of three geometric figures and one bird-like figure were completed by children 3-5 years of age ("N" = 99). The rotation effect, in which the correct response decreased with orientation (45°, 90° 135°, and 180°), was confirmed, except in one of the geometric conditions. We found that two factors were needed for a child to perform the bird-like completion task: clarification of the reference to each stimulus and awareness of the turning orientation. These studies suggest that the children processed the contour and feature information individually, and that the contour information was processed earlier than the feature information. We derived three criteria for sensitive information to resolve the task, contact, contour, and left-right. Findings are discussed with regard to the reference action and the part-whole relationship.