Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 52 6 2023 06 13 1190 1198 EN Chunjing Tu School of Teacher Education, Taizhou University, Taizhou, China Yuxuan Tu Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China Chongmin Jiang China Institute of Sport Science, Beijing, China Sanhua Zhang College of Education, Hangzhou Normal University, Hangzhou, China 2022 12 22 2023 04 25 Background: We aimed to establish the cut-off value of weight-for-height for preschool children in China, and to explore the influence of overweight and obesity on the physical performance of preschool children. Methods: Data from 31 provinces in China monitored in 2010 and 2014, the standard deviation unit curves of WFH were established by using GAMLSS (generalized additive model for location, scale, and shape) method preschool children in China, and then the cut-off values of normal weight, overweight and obesity were divided. The research group tested 5 physical performance indicators of 5154 preschool children from April 2018 to June 2019 in Beijing and Zhejiang in China. We then compared physical performance differences between the normal-weight group and the overweight-obesity group. Results: A smooth and effective standard deviation unit curve of WFH was established. The overweight and obesity of Chinese preschool children were at a high level. Being overweight and obese reduced preschool children's relative strength, speed, sensitivity, coordination, and balance ability, but did not reduce preschool children's flexibility. In general, the physical performance of preschool children in the normal weight group was better than that in the overweight and obesity group. Conclusion: It is suggested to use the WFH criteria in this study to evaluate overweight and obesity in Chinese preschool children, and strengthen physical activity and take in energy substances properly of preschool children, to control the spread of overweight and obesity， to improve physical performance level.   https://ijph.tums.ac.ir/index.php/ijph/article/view/30742 https://ijph.tums.ac.ir/index.php/ijph/article/download/30742/7957