Abstract: Objective: To comprehensively assess the association between sedentary behavior and anxiety symptoms in children and adolescents by means of a systematic review method, so as to provide an evidence-based understanding of the impact of sedentary behavior on mental health. Methods: A comprehensive literature search was conducted in PubMed, Embase, Web of Science, Cochrane Library, CNKI, WanFang, and VIP databases from inception to August 31, 2025. Cohort studies investigating the relationship between sedentary behavior or screen time and anxiety symptoms were included. The Newcastle-Ottawa scale was used to assess the risk of bias in the included studies. A qualitative synthesis was performed to analyze the types of sedentary behavior, measurement methods, and their associations with anxiety symptoms. Results: Six cohort studies involving a total of 18,572 children and adolescents were included. Most studies indicated a positive association between sedentary behavior and anxiety symptoms, although significant heterogeneity was observed across studies, with some reporting non-significant associations. Further analysis suggested that recreational screen time was more consistently associated with anxiety symptoms. Conclusion: Current evidence suggests that increased sedentary behavior, particularly recreational screen use, may be associated with an elevated risk of anxiety symptoms in children and adolescents. Future research should employ mixed-method approaches combining subjective and objective measures to better differentiate types of sedentary behavior and elucidate the underlying mechanisms linking sedentary behavior to anxiety, so as to provide a scientific basis for formulating targeted preventive and intervention strategies.