Objective The study aimed to analyze the independent and joint associations of physical activity (PA) and sedentary behavior (SB) with self-rated health (SRH) among Chinese children and adolescents. Methods Cross-sectional data on moderate-to-vigorous physical activity (MVPA), school-based PA, extracurricular physical activity (EPA), screen time (ST), homework time, and SRH were assessed through a self-report questionnaire in the sample of 4227 Chinese children and adolescents aged 13.04 +/- 2.62 years. Binary logistic regression was used to compare gender differences in PA, SB, and SRH among children and adolescents, and analyses were adjusted for age and ethnicity. Results In independent associations, boys and girls engaging in >= 60 min/day of MVPA and >1 hour/day of EPA reported optimal SRH. Only boys who participated in >1 hour/day of school-based PA were significantly more likely to have optimal SRH (OR = 1.49, 95%CI = 1.19-1.86). Only girls who had <= 2 hours/day of ST were significantly associated with optimal SRH (weekdays: OR = 1.38, 95%CI = 1.10-1.74; weekends: OR = 1.40, 95%CI = 1.14-1.71; whole week: OR = 1.42, 95%CI = 1.16-1.73). In joint associations, regardless of SB recommendation, meeting PA recommendation was significantly associated with optimal SRH in both boys (meet PA and SB recommendations, OR = 1.61, 95%CI = 1.03-2.50; meet PA but not SB recommendations, OR = 2.40, 95%CI = 1.57-3.65) and girls (meet PA and SB recommendations, OR = 3.72, 95%CI = 2.08-6.65; meet PA but not SB recommendation, OR = 4.27, 95%CI = 2.09-8.75). Conclusion Increased PA and reduced SB were positively associated with optimal SRH in Chinese children and adolescents. Notably, lower ST positively influenced only girls' SRH. Meeting PA recommendation is more impactful than meeting SB recommendation for improving SRH in Chinese children and adolescents. Future studies could explore these associations using objective measures of PA and SB in China.