This study aims to explore the mediating effect of mobile phone dependence between“weight anxiety”and depressive symptoms among adolescents，therefore providing a basis for the management and prevention of adolescent mental health. Electronic questionnaires were distributed in 12 schools from November 2021 to March 2022 using the multi-stage stratified cluster random sampling method. A total of 9 225 adolescents finished the survey，which included a general questionnaire，a“Weight Anxiety”Questionnaire，a Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use，and the Center for Epidemiologic Studies Depression Scale（CE-D10）. The results showed that“weight anxiety”was positively associated with depressive symptoms（β=0.39，P＜0.001）. Mobile phone dependence mediated the relationship between different manifestations of“weight anxiety”and depressive symptoms，with indirect effects of 14.29% ，14.91% and 22.08% ，respectively. In conclusion，mobile phone dependence mediates the relationship between“weight anxiety”and depressive symptoms among adolescents. Individuals who are highly concerned about and sensitive to their body weight may contribute more to this indirect effect.