AbstractsIn light of the novel coronaviruss (COVID-19s) threat to public health worldwide, we sought to elucidate COVID-19s impacts on the mental health of children and adolescents in China. Through online self-report questionnaires, we aimed to discover the psychological effects of the pandemic and its associated risk factors for developing mental health symptoms in young people. We disseminated a mental health survey through online social media, WeChat, and QQ in the five Chinese provinces with the most confirmed cases of COVID-19 during the late stage of the country-wide lockdown. We used a self-made questionnaire that queried children and adolescents aged 6 to 18 on demographic information, psychological status, and other lifestyle and COVID-related variables. A total of 17,740 children and adolescents with valid survey data participated in the study. 10,022 (56.5%), 11,611 (65.5%), 10,697 (60.3%), 6,868 (38.7%), and 6,225 (35.1%) participants presented, respectively, more depressive, anxious, compulsive, inattentive, and sleep-related problems compared to before the outbreak of COVID-19. High school students reported a greater change in depression and anxiety than did middle school and primary school students. Despite the fact that very few children (0.1%) or their family members (0.1%) contracted the virus in this study, the psychological impact of the pandemic was clearly profound. Fathers anxiety appeared to have the strongest influence on a childrens psychological symptoms, explaining about 33% of variation in the childs overall symptoms. Other factors only explained less than 2% of the variance in symptoms once parents anxiety was accounted for. The spread of COVID-19 significantly influenced the psychological state of children and adolescents. It is clear that children and adolescents, particularly older adolescents, need mental health support during the pandemic. The risk factors we uncovered suggest that reducing fathers anxiety is particularly critical to addressing young peoples mental health disorders in this time.