Objective To observe the effect of community intervention of parent-child relationship on parents-grandparents coparenting in Beijing urban area,and provide a basis for appropriate community care model on children mental health care. Methods From December 2013 to March 2014,a total of 203 children aged from 4 to 11 months old and their families in 4 communities of two districts in Beijing were studied.4 communities were randomly divided into study group and control group.In the study group,children's caregivers were given personalized skills guidance and counseling,and were given lectures on children health care and parent-child relationship once a month.Children's caregivers of the control group were given routine child health examination and guidance.A self-designed questionnaire was used to investigate all participants after 1 year. Results The existing prominent problems of parents-grandparents coparenting in families of both groups were lack of communication and coparenting conflict.The proportions of families in which grandparents supported (P< 0.01) and cooperated (P=0.046) with children's parents in the study group were higher than that of the control group.The proportions of families in which grandparents had disagreements (P=0.046) with children's parents and disparaged (P=0.04) them in the study group were lower than that of the control group. Conclusion s Community intervention of parent-child relationship improves the cooperation of grandparents and parents,reduces the differences of child rearing,and the behavior undermining parent-child relationships.However,its effect on other dimensions of coparenting is not significantly.It is recommended to further improve the community intervention strategies of parent-child relationship.