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.