Abstract: ObjectiveTo evaluate the effects of the environment factors on diseases and symptoms of respiratory system of the students in Lanzhou and select major dangerous factors.MethodsBased on monitored level of air pollution materials in the heating period in 2005.The questionnaire survey about the diseases and symptoms of respiratory system were investigated among the primary and middle school students aged 8～20 years in Xigu area(severe air pollution area),Chengguan area (relatively less pollution area)and Yuzhong area(relatively clean area).ResultsThe air pollution level and respiratory symptoms and diseases prevalence showed Xigu area>Chengguan area>Yuzhong area.By Logistic regression,after controlled other factors,it could be demonstrated that the risk factors of the respiratory symptoms and diseases were the air pollution,indoor air pollution and smoking.ConclusionThe air pollution,indoor air pollution and smoking were the main factors to affect the healthy of respiratory system of the students.