Abstract: Objective To investigate the influence of gestational diabetes mellitus(GDM) on body size and blood lipid level of preschool offspring.Methods A total of 640 GDM offsprings were enrolled from “Tianjin GDM Prevention Program”. According to World Health Organization child development level standard 2006, and control of hyperlipid in children and adolescents in China was used to analyze blood lipid level.Results There was no significant difference in the Z score of height and weight among children of different ages(P> 0. 05). With the increasing of age, the body mass index(BMI) Z score increased, and the proportion of overweight and obesity also increased. Boys' mean scores of weight and BMI were significantly higher than girls'(P< 0. 05). The total detection rate of dyslipidemia in children of GDM offspring was 20. 8%(133/640). There was no significant age trend observed in the results of blood lipid test. There was no gender difference in term of level of total cholesterol and the abnormal detection rate. Density lipoprotein cholesterol among boys were higher than girls, while boys with low density lipoprotein cholesterol and total triglyceride(TG)were significantly lower than girls(P< 0. 05). TG level and abnormal detection rate in children of different obese degrees were significantly different(P< 0. 05).Conclusion Growth and development, occurrence of hyperlipid of GDM offspring at preschool age are characteristic and gender different, which is meaningful for individual and group prevention of obesity and metabolic abnormalities.