Objective To investigate the possibility of gestational body weight intervention and its influence on pregnancy outcomes.Methods 300 healthy primiparae with normal pregestational BMI and living monoeyesis and head presentation were randomly divided into the observation group (n = 120) and control group ( n = 180).Both groups were received general health education and regular obstetric examination, in addition, the observation group received body weight intervention.The data about changes in BMI and body weight from pregestation to ante partum were collected and pregnancy outcomes were assessed.Results The incidence of △ BMI≥6,gestensive hypertension, diabetes, cesarean section,large-for-date infant,intrauterine fetal distress,postparum hemorrhage in the observation group was significantly lower than those of the control group( x2 = 19.265,4.903,6.875,13.522,7.354,4.545,3.993, all P < 0.05).Conclusion Body weight intervention had a preferable feasibility and could improve pregnancy outcome.