Objective: To investigate the relationship between daily outdoor activity time both on and off campus and respiratory symptoms of junior middle school students, then to provide evidence for the prevention of respiratory diseases in adolescents. Methods: In 2016, two middle schools were selected in Wuhan，in which a total of 860 eighth grade students were surveyed, generalized linear analysis was conducted by SAS 9.4 software. Results: Average outdoor activity time out of campus during weekdays in boys and was (1.84±2.30) hours, which was higher than in girls (1.51±1.99) hours (t=2.19, P<0.05). Average outdoor activity time in campus in boys was (1.74±1.50) hours, which was significantly higher than that of girls (1.49±1.20) hours (t=2.68, P<0.05). According to the results of generalized linear analysis, after controlled for gender, age and self-perceived physical condition, the longer the time adolescents spent outside the classroom during weekday, the less likely they were to have symptoms of throat and nasal cavity(estimated value=-0.06,-0.07, P<0.05). Conclusion Adolescents who spend more time outside the classroom during weekday can effectively prevent the occurrence of respiratory related diseases.