Abstract: ObjectiveTo study the relationship between birth weight and child simple obesity so as to provide reference for children obesity prevention and control.MethodsA1B1 matched case-control study was carried out by using questionnaire.The relationship between birth weight and child simple obesity were analyzed.ResultsMatched case-control study analysis showed the risk of simple obesity for children with high birth weight was 2.29 times for that of children with normal birth weight(P<0.01),and low birth weight was 2.00 times for that of children with normal birth weight(P>0.05).Curve estimation study showed/U0 shape distribution between BMI of children and birth weight(P<0.05).ConclusionChildren simple obesity could be affected by high birth weight and low birth weight.