Abstract: Background:One indication of the use of health services by the community is the activeness of the arrival of the community to the health service center, in this case specifically the utilization of posyandu services, namely the activity of parents bringing their children to the posyandu. Factors that influence the behavior of mothers under five in the use of posyandu are family knowledge and support. Based on preliminary studies in several journals, there are differences in the results of research on the variables of knowledge and family support with the behavior of mothers under five in the use of posyandu.