A study was conducted on 207 preschool chlidren from 3 to 5 years of age studing at Anh Sao school, Ba Dinh district and at Sac Mau school, Hoang Mai district. Anthrophometric and social methods were used to evaluate overweight and obesity situations and to assess related factors. Results showed that: The rate of obesity of preschool children from 3 to 5 years of age was relatively high (13.04 percent). Factors related to overweight and obesity situations of preschool children were playing activities of children, economic circumstances of children families, numbers of children in a family, and education levels of parents. WHO Anthro 2.04 is a useful software to assess growth of children at schools and families.