Objective: To investigate the relationship between attachment to pets and psychosecial develop-ment of children. Methods: Totally 147 children pet owners from grade 3 to grade 5 were selected from 11 primary schools in Beijing. They were asked to complete the Lexington Attachment to Pets Scale, Self Description Question-naire, Children's Loneliness Scale, and 2 dimensions of Children Social-life Adjustment Scale. Results: Attach-ment to pets was positively correlated with self-concept, pro-social orientation and living ability of daily life (r=0.47, 0.42, 0.34, Ps < 0.001), and negatively correlated with loneliness (r=-0.28, P <0.01) . Even the variables including study performance, interrelationship and socioeconomic status of family were taken as covari-ares, the higher attach group was better than lower attach group in self-concept, pro-social orientation, living abili-ty of daily life [(163.81±17.81)vs.(138.36±27.71), (46.19±4.25)vs.(40.64±6.93), (39.05±4.17)vs.(33.77±6.51); Ps<0.001] and loneliness [(28.53±11.08)vs.(34.79±10.96); P <0.01].Conclusion: There is apparent relationship between pet attachment and psychosocial development in children.