Abstract： Objective:To explore the relationship between body composition and the risk of gestational diabe-tes mellitus(GDM)in pregnant women.Methods:90 pregnant women with spontaneous pregnancy of singleton who underwent routine prenatal examination in our hospital were selected as GDM group,and 219 pregnant women with normal singleton in the same period as control group(NGT).The body composition was determined by bioimpedance method at 24-28 weeks of gestation.The relationship between body mass index(BMI),per-centage of body fat(FMP),percentage of fat-free body weight(FFMP),extracellular/intracellular fluid(ECW/ICW),body fat index(FMI)and GDM were analyzed.The levels of circulating adiponectin,fatty acid binding pro-tein 4(FABP4),leptin and fasting insulin(FINS)were measured by enzyme linked immunosorbent assay(ELISA)method,and their relationship with various indicators of human body composition was analyzed.Results:①Adi-ponectin in GDM group was lower than that in NGT group,while leptin was higher than that in control group(P＜0.05).②The FMP,ECW/ICW and FMI in GDM group were significantly higher than those in control group(P＜0.05).Univariate regression analysis showed that BMI,FMP,FMI and ECW/ICW before pregnancy were the risk factorsof GDM(OR＞1,P＜0.05),FFMP,MP,PP and M/F was the protective factor of GDM(OR＜1,P＜0.05).Multivariate analysis showed that only FMP was significantly correlated with the risk of GDM,which was an independent risk factor(OR＞1,P＜0.05).③In GDM group,HOMA-IR was positively correlated with FMI(r＞1,P＜0.05)and negatively correlated with PP(r＜1,P＜0.05).④The ROC curve showed that the diagnostic value of pre-pregnancy BMI、FMP、ECW/ICW and FMI in GDM was similar.There was no significant difference in pre-pregnancy BMI,FMP and FMI(P＞0.05),but they were slightly better than ECW/ICW(P＜0.001).Conclu-sions:Body composition during pregnancy is related to the risk of gestational diabetes.The increase in FMP is associated with an increased risk of developing GDM.The higher the FMP,the higher the risk of GDM.The diag nostic efficacy of BMI,FMP and FMI in GDM is Similar.