目的·了解新冠疫情大流行期间儿童及青少年的新发焦虑症状，分析影响该症状的相关因素。方法·依托成都儿童正向成长（Chengdu Positive Child Development，CPCD）队列，纳入成都市5所中小学的儿童和青少年共5 566例，分别建立儿童和青少年新发焦虑症状纵向研究队列并开展2轮调查。第一轮调查（基线调查）的时间为2019年12月—2020年1月，通过促进儿童青少年正面成长研究学生调查问卷收集队列成员的一般人口学特征信息；第二轮调查（随访调查）的时间为2020年2—7月，补充收集队列成员的新冠病毒感染史，以及饮食、学习、社交和娱乐活动是否受到新冠疫情的影响等信息。利用儿童焦虑性情绪障碍筛查表（Screen for Child Anxiety Related Emotional Disorders，SCARED）评估所有研究对象的新发焦虑症状。采用多因素Logistic回归模型对儿童和青少年新发焦虑症状的影响因素进行分析。结果·SCARED评估结果显示，在新冠疫情大流行期间成都儿童及青少年新发焦虑症状的发病率为13.47%；其中儿童新发焦虑症状纵向研究队列中的发病率为11.91%，青少年新发焦虑症状纵向研究队列中的发病率为14.25%。χ²检验的结果显示，儿童新发焦虑症状的发病率在年龄、本人或家人是否感染新冠病毒，以及饮食、学习和社交活动是否受到影响间的差异具有统计学意义（均P<0.05）；青少年新发焦虑症状的发病率在性别、年级、年龄、居住地区，以及饮食、学习、社交和娱乐活动是否受到影响间差异亦具有统计学意义（均P<0.05）。多因素Logistic回归分析的结果显示：对儿童来说，6~8岁是其新发焦虑症状的保护因素，而本人或家人感染过新冠病毒、学习活动受到影响是其危险因素（均P<0.05）；对青少年来说，男性、居住在城镇、年级≤6是其新发焦虑症状的保护因素，而学习活动受到影响是其危险因素（均P<0.05）。结论·对于儿童和青少年来说，在新冠大流行期间影响其新发焦虑症状的因素并不完全一致；对于儿童来说，年龄、本人或家人是否感染新冠病毒、学习是否受到影响是其新发焦虑症状的独立影响因素，但对青少年来说则是性别、年级、居住地区和学习是否受到影响。因此，在动态关注儿童和青少年心理健康状态、持续做好心理健康干预工作过程中，应遵循成长规律，充分考虑儿童和青少年的发展特点，采取不同的策略和措施。

Objective ·To investigate the occurrence of new onset anxiety symptoms in children and adolescents during the COVID-19 epidemic, and analyze the influencing factors. Methods ·Based on Chengdu Positive Child Development (CPCD) cohort, a total of 5 566 children and adolescents from five primary and secondary schools in Chengdu were enrolled. Two longitudinal study cohorts of new anxiety symptoms in children and adolescents were established, and two rounds of survey were conducted. The first round of survey (baseline survey) was conducted from December 2019 to January 2020, and the general demographic characteristics of the cohort members were collected through the Student Questionnaire for the Study on Promoting Positive Growth of Children and Adolescents. The second round of survey (follow-up survey) was conducted from February to July 2020 to collect additional information on the cohorts' infection history of COVID-19, and whether their eating, learning, and social and recreational activities were affected by the COVID-19 epidemic. The Screen for Child Anxiety Related Emotional Disorders (SCARED) was used to evaluate the new onset anxiety symptoms of all subjects. The multivariate Logistic regression model was used to analyze the influencing factors of new onset anxiety symptoms in children and adolescents. Results ·The results of SCARED assessment showed that the incidence of new onset anxiety symptoms among children and adolescents in Chengdu during the COVID-19 epidemic was 13.47%. In the longitudinal study cohort of new onset anxiety in children,the incidence was 11.91%, and in the longitudinal study cohort of new onset anxiety in adolescents, the incidence was 14.25%. The results of chi square test showed that there were statistically significant differences in the incidence of new onset anxiety symptoms among children in terms of age, whether they or their family members were infected with COVID-19, and whether their eating, learning and social activities were affected (all P<0.05); there were also statistically significant differences in the incidence of new onset anxiety symptoms among adolescents in gender, grade, age, residential area, and whether their eating, learning, and social and recreational activities were affected (all P<0.05). The results of multivariate Logistic regression analysis showed that, for children, 6?8 years old was the protective factor for their new onset anxiety symptoms, while they or their family members infected with COVID-19 and the impact of their learning activities were the risk factors (all P<0.05); for adolescents, males, residing in urban areas, and grades ≤ 6 were the protective factors for their new onset anxiety symptoms, while the impact of their learning activities was the risk factor (all P<0.05). Conclusion ·For children and adolescents, the factors that affect their new onset anxiety symptoms during the COVID-19 epidemic are not completely the same. For children, age, whether they or their family members are infected with COVID-19, and whether their learning is affected are independent influencing factors; but for adolescents, gender, grade, residential area, and whether their learning is affected are independent influencing factors. Therefore, in the process of dynamically paying attention to the mental health status of children and adolescents and continuously doing a good job of mental health intervention, it is necessary to follow the law of growth, fully consider the developmental characteristics of children and adolescents, and adopt different strategies and measures.