Abstract: Objective To examine the prevalence of common diseases among primary and middle school students in Hangzhou city and to provide a scientific basis for intervention on risk factors of the diseases in the students.Methods With stratified cluster random sampling,the datasets of annual physical examination and screenings of malnutrition,obesity,poor sight,dental caries,and trachoma in 109 777 and 115 369 students from 105 primary and middle schools in 2009 and 2010 school year were collected and analyzed.Results Among the students,poor eyesight was the most prevalent health problem,with an increased prevalence from 69.99% in 2009 to 72.63% in 2010(χ²=187.76,P<0.001) and the second prevalent illness was dental caries,with an increased prevalence from 22.46% to 24.93%(χ²=189.05,P<0.001).During the two-year periold,the prevalence of malnutrition decreased slightly from 6.96% to 6.30%(χ²=39.09,P<0.001),while that of obesity oppositely increased from 12.76%to 13.51%(χ²=27.84,P<0.001).Conclusion In primary and middle school students of Hangzhou city,the prevalence of common diseases increased from 2009 to 2010,except for malnutrition;the results of the study indicate that health conditions of the students need to be concerned.