The purpose of this study was to explore whether evaluations of the behavioral attributes of only children in Beijing differed from evaluations of children with siblings, and how these evaluations were affected by gender and China's One-Child Policy (OCP). This study applies hierarchical linear regression analyses to data collected from children born before or after the initiation of the OCP. The participants (N = 1000) were randomly selected schoolchildren whose behavioral attributes were evaluated by the children themselves, their peers, parents, and teachers, using a 32 attributes checklist, consisting of attributes Chinese experts considered important for school-aged children. In addition, a difference score, representing the difference between self and peer evaluations, was considered in order to assess degrees of self-enhancement. The results indicated that male only children received less positive self, peer, parent, and teacher evaluations than female only children and that among children born before the OCP, only children evaluated themselves less positively than their peers with siblings. Parents evaluated their only children born after the OCP more positively than did parents of only children born before the OCP. In terms of self-enhancement, only children, particularly male only children, evaluated themselves more positively than they were evaluated by their peers. These findings are discussed in terms of the major social and cultural changes happening in China since the OCP that affected how only children saw themselves and were seen by others.