Abstract: Objective To explore the intervention effect of medical nutrition therapy on pregnancy outcomes of pregnant women with gestational diabetes mellitus (GDM).Methods From 2013 to 2014, pregnant women with GDM who received prenatal examination and completed follow-up visits were randomly selected as the research subjects from Changzhou maternal and children's health care hospital.Among these cases, 281 cases who voluntarily accepted personalized medical nutrition therapy (MNT) were selected as intervention group (Group A).And, 304 cases who just only received general nutrition guide were selected as control group (Group B).At the same time, according to the results of glucose tolerance, the control group and the intervention group were respectively divided into three groups:A1 (one abnormal glycemic index), B1;A2 (two abnormal glycemic indexes), B2;A3 (three abnormal glycemic indexes), B3.A controlled study was used to compare the incidence of maternal and neonatal complications and to assess the pregnancy outcomes of different types of pregnant women with GDM.Results Compared with the control group, the ratio of using insulin、the incidence of anemia and fetal macrosomia of the intervention group were lower (P<0.05).However, the incidence of cesarean section of the intervention group was higher than that of the control group (P<0.05).Compared with group B1 and B2, it was obvious that the probability of occurrence of maternal and neonatal complications after MNT in group A1, A2 was lower (P<0.05).However, compared with group B3, the effect of MNT in group A3 was not significant, and the difference had no statistical significance between the two groups (P>0.05).Conclusion For GDM pregnant women with less than two abnormal glycemic indexes at different time points, using personalized medical nutrition therapy can achieve better pregnancy outcome.However, for GDM pregnant women with three abnormal glycemic indexes, the insulin therapy should be used timely in order to effectively reduce the occurrence of maternal and neonatal complication among GDM pregnant women.