Social adjustment is the continuous learning or modification of various behaviors and lifestyles by individuals in the process of interaction with the social environment. Social adjustment is important for children's sociality, academic development and future well-being. It can directly lead to various externalized and internalized problems of children. According to the ecological theory of human development, peer group is one of the important factors affecting the development of children. Peer acceptance reflects the likeness, popularity and social status of an individual in a group and indicates the positive peer relationship of children. Many studies have identified that a high level of peer acceptance is conducive to children's positive social adjustment and reduces their problem behaviors. According to the theory of peer attachment, children's own adjustment problems will in turn affect their peer relationships. Many studies have also found that children's social adjustment also has a direct prediction effect on their peer acceptance. Higher social competence and less problem behaviors can also improve children's peer acceptance. Some limitations of previous studies are as follows. Firstly, most of the existing studies discuss the one-way prediction relationship between the peer acceptance and social adjustment.Secondly, most studies in this area have focused on one aspect of social adjustment but not all. Thirdly, most researches concentrated on the field of adolescents but pay less attention to preschool children. Therefore, this study used a tracking design of three time points to explore the correlation between peer acceptance and social adjustment in early childhood. Participants were 192 pre-school children from two public kindergartens in Shanghai, including 114 boys and 78 girls. The study adopted longitudinal design at 3 times over the course of 1.5 year. The data were collected at the beginning of the middle class for the first time (mean age 4.28±0.31 years old at Time 1), one year later for the second time(mean age 4.95±0.31 years old at Time 2), and a half years later for the third time（mean age 5.53±0.31 years old at Time 3）. Peer acceptance was measured through peer nomination procedure. The specific procedure was that the participants were asked to select the top three students in their class who liked and did not like to play together. Children's social competence was measured by the Chinese version of the social competence and behavior scale, and the internal consistency and reliability of the social ability subscale of the three tests were between .84 and .90. The internalized and externalized problem behaviors of children were measured by the Chinese version of social skill scale, and the internal consistency reliability of the three measures was between .87 and .92. The results indicated that: (1) peer acceptance at time 1, social competence and externalized problem behaviors at time 2 could significantly predict each other; internalized problem at time 1 could significantly predict peer acceptance at time 2. (2) Similarly, peer acceptance at time 2 and social competence at time 3 can influence each other; and peer acceptance at time 2 can predict externalized problem behaviors at time 3. (3) Peer acceptance did not predict children's internalized problem behaviors, nor did internalized problem and externalized problem at time 2 significantly predict children's peer acceptance at time 3.