AIM:To determine the incidence of myopia and related risk factors among Chinese school-age children in Suqian city.METHODS: The data were collected from 42 primary schools in Suqian, Jiangsu Province with a stratified cluster sampling method. According to the physical examination information in 2019 and 2020, a total of 12 452 school-age children were included. Based on their two-year information of visual acuity, diopter, height and weight, this study analyzed the incidence of myopia under different demographic factors and related risk factors among school-age children.RESULTS: It was found that the overall incidence rate of myopia among school-age children was 24.63% in Suqian(all P<0.01). Higher incidence rates of myopia occurred in the urban children than rural children(26.24% vs 21.31%), in females than males(27.05% vs 22.91%)and in overweight children than normal ones(25.82% vs 23.92%). The incidence also showed an increasing trend with age(χ2trend=236.421,P<0.01). For the growth and development, the annual increases of height and weight in incident myopia were greater than that in persistent non-myopes(allP<0.01). The Logistic regression analysis confirmed that urban children(OR=1.541), females(OR=1.325), elder-ages(OR=2.827)and overweight children(OR=1.191)were at higher risk of myopia onset(all P<0.01).CONCLUSION: The incidence of myopia among school-age children from Suqian City in 2020 was alarming. And urban children, females, elder and overweight school-age children were at relatively higher risk of myopia onset. Additionally, the rapid increase of height and weight over a period of time may be one of the warning signals for myopia onset. The factors impacting on the myopia onset among children warrants further studies.