Abstract: Objective To analyze the situation of physical activity among school-aged children and adolescents in Shanghai,and to provide a scientific basis for physical education and health pronotion.Methods A questionnaire survey of physical exercise behavior was conducted among 12 646 students aged 9-18 years old in primary and middle school students in 6 districts of Shanghai in 2014.Results In the survey,40.2% of the students had physical activity more than one h each day,and the rates of the primary,middle and high school students having physical activity more than one h each day were 60.9%,39.0% and 19.1%,respectively(x2=1 341.014,P<0.01);The proportion of obese students in daily exercise to 1 h was significantly (44.2%) higher than that of normal students(39.4%) (x2 =9.115,P<0.01).About 60.5% of the students sweated and felt a little bit tired in PE,and 78.4% of students liked PE class,and 82.6% of the students liked to take part in extracurricular sports activities.In addition,51.5% of the students liked to participate in long-distance running.The survey found that the main reason for students' not actively participating in physical activities and long-distance running was "fear of fatigue,fear of hardship"(62.5%,80.3%).Conclusion The prevalence of having been physically active for a total of at least 1 h per day was higher than the global average,and there were differences among different groups.Therefore,we should pay attention to the combination of physical exercise effect evaluation and process evaluation,fully mobilize the enthusiasm of students to participate in physical exercise,and cultivate students' lifelong exercise habits.