目的 :了解体块指数 (BMI)在儿童期的发育规律 ,为儿童肥胖的评价提供依据。方法 :采用Cole的LMS法 ,该法调整了BMI分布的偏度。结果 :城乡男女生体块指数的发育规律不同 ,女生比男生早 ,城市比农村早 ,并提供了西安市 1 995年 0～ 1 8岁儿童青少年体块指数百分位数图。结论 :儿童肥胖可采用体块指数百分位数评价 ,本文计算的年龄别百分位数可作为临床应用的参考标准 Objective: To understand the development of body mass index (BMI) in childhood and provide the basis for the evaluation of childhood obesity. METHODS: Cole’s LMS method was used to adjust the skewness of the BMI distribution. Results: The body mass index of boys and girls in urban and rural areas had different developmental patterns. The girls were earlier than boys and the cities were earlier than the rural areas. The figure of percentile of body mass index of children and adolescents aged from 0 to 18 in Xi’an in 1995 was provided. Conclusion: Child obesity can be assessed by the body mass index percentile. The age percentile calculated in this paper can be used as a reference standard for clinical application