目的 研制中国11市汉族（胎龄26~41周）和壮族（胎龄28~41周）单胎儿出生体重曲线及14个民族足月单胎儿出生体重均值。 方法 对中国11市11家妇幼保健院2017年1月—2020年12月分娩的活产单胎儿，按母亲民族分类，计算各民族足月儿出生体重均值，并采用Lambda-Mu-Sigma（LMS）方法对其中样本量大的汉族和壮族绘制不同胎龄单胎儿出生体重百分位曲线。 结果 共纳入105 365例单胎活产新生儿，其中汉族纳入数量最多（84 851例，胎龄26~41周），其次为壮族（12 803例，胎龄28~41周）；其他民族纳入的均为足月单胎活产新生儿，各民族样本量均在100例以上。制定了汉族（胎龄26~41周）和壮族（胎龄28~41周）单胎儿出生体重3rd~97th百分位曲线；汉族单胎儿出生体重曲线水平高于壮族。获得了黎族、仫佬族、壮族、瑶族、侗族、苗族、汉族、布依族、蒙古族、土家族、彝族、回族、满族、朝鲜族等14个民族足月单胎儿出生体重均值和标准差（均值为3 199~3 499 g）；出生体重水平从低到高排位依次为：黎族、仫佬族、壮族、瑶族、侗族、苗族、汉族、布依族、蒙古族、土家族、彝族、回族、满族、朝鲜族。 结论 制定了中国11市汉族（胎龄26~41周）和壮族（胎龄28~41周）单胎儿出生体重3rd~97th百分位曲线及中国11市14个民族足月儿出生体重均值，可为这些民族新生儿宫内生长评价提供参考。

Objective To develop the birth weight curves of the Chinese Han (26-41 weeks of gestation) and Zhuang (28-41 weeks of gestation) singleton neonates in 11 cities of China, as well as the birth weight means of full-term neonates of 14 Chinese ethnic groups. Methods The live singleton neonates who were born in 11 maternal and child health care hospitals from 11 cities of China between January 2017 and December 2020 were classified according to the mother's ethnic group. Birth weight means were calculated for the full-term neonates of each ethnic group. For the Han and Zhuang singleton neonates with a large sample size, the Lambda-Mu-Sigma (LMS) method was used to establish the birth weight percentile curves of the Han and Zhuang singleton neonates with different gestational ages. Results A total of 105 365 live singleton neonates were included, among whom the Han neonates had the highest number of 84 851 (26-41 weeks of gestation), followed by the Zhuang neonates (12 803 neonates with a gestational age of 28-41 weeks). The neonates of the other Chinese ethnic groups enrolled were live full-term singleton neonates, with a sample size of more than 100 neonates for each ethnic group. The 3rd-97th percentile curves of birth weight were established for the Han singleton neonates with a gestational age of 26-41 weeks and the Zhuang singleton neonates with a gestational age of 28-41 weeks. The birth weight curves of the Han singleton neonates at each gestational age were higher than those of the Zhuang singleton neonates. Birth weight means (3 199-3 499 g) and standard deviations were determined for 14 Chinese ethnic groups, i.e., Li, Mulao, Zhuang, Yao, Dong, Miao, Han, Buyi, Mongolian, Tujia, Yi, Hui, Man, and Korean ethnic groups. The Li ethnic group had the lowest birth weight, followed by the Mulao, Zhuang, Yao, Dong, Miao, Han, Buyi, Mongolian, Tujia, Yi, Hui, Man, and Korean ethnic groups. Conclusions The 3rd-97th percentile curves of birth weight are developed for the Han (26-41 weeks of gestation) and Zhuang (28-41 weeks of gestation) singleton neonates in 11 cities of China, and birth weight means are determined for the full-term neonates of 14 Chinese ethnic groups in 11 cities of China, which provides a reference for evaluating the intrauterine growth of neonates in these ethnic groups.