Objective: To investigate the association between 24 h movement behaviors (physical activity, sleep, and screen time) and fundamental motor skills (FMS) in preschool children, in order to provide the reference and basis for ensuring the longterm development of childrens motor skills. Methods: A total of 607 children aged 3 to 5 years old were selected from 6 kindergartens of 6 urban districts in Taiyuan in March 2022, through a combination of convenient sampling and stratified cluster random sampling method, and the baseline test was conducted to collect data on the childrens 24 h movement behaviors and FMS; the followup test after one year was carried out in March 2023 to collect FMS data. The test of gross motor development-3rd was used to assess the childrens FMS levels. Physical activity and sleep duration were measured using ActiGraph GT3X+ accelerometers, while screen time was reported by parents. Pearson correlation analysis, hierarchial and binary Logistic regression analyses were used to analyze the association of 24 h movement behavior with FMS. Results: The results of baseline showed that total of physical activity (TPA) at baseline was positively associated with manipulation skills, mobility skills and total score of TGMD-3 (β=0.40, 3.87, 4.27, P<0.01). The followup results after one year indicated that lowintensity physical activity (LPA) and screen time at baseline were negatively associated with increased TGMD-3 scores one year later (β=-1.93, -0.79, P<0.01). Conversely, baseline moderatetovigorousintensity physical activity (MVPA), TPA and sleep duration were positively associated with increased TGMD-3 scores after one year (β=4.62, 4.51, 3.19, P<0.01). The followup results showed that meeting 2 or 3 items of the 24 h movement behavior guidelines was significantly associated with an increased likelihood of achieving motor skill proficiency (OR=2.31, 3.32, P<0.01) compared to not meeting any 24 h movement behavior guideline after one year. Conclusions MVPA and enough sleep could positively affect FMS improvement, whereas LPA and long screen time could negatively affect FMS improvement at one year followup. Schools and families should ensure that preschool children meet the recommended standards of the 24 h movement behavioral guidelines to promote longterm development of FMS.