Objective To investigate the prevalence of mental disorders in school students aged from 6 to 16 years in Zhenjiang， Jiangsu Province. Methods Students from 12 primary and secondary schools were surveyed by multistage stratified cluster random sampling and two stage survey. The students were first screened by the Chinese version of the Child Behavior Scale（ CBCL）， and then diagnosed by the International Neuropsychiatric Interview（ MINI KID）. Results Among the 6 576 students who completed the survey， 1 392 were positive for CBCL screening， with a detection rate of 21.17%（ 1 392/6 576）（ 95%CI=20.18%-22.16%）. The prevalence of mental disorders was 4.08%（ 95%CI=3.60%-4.55%）， of which 37.31%（ 100/268） had two or more mental disorders. There was no statistically significant difference in the prevalence between boys（ 3.84%， 122/3 178） and girls（ 4.30%， 146/3 398）. The prevalence of students aged from 6 to 11（ 3.03%， 92/3 032） was lower than those aged from 12 to 16（ 4.97%， 176/3 544）， and the difference was statistically significant （P＜0.05）. Prevalence of the city students（ 2.46%， 82/3 339） was lower than that of the rural students（ 5.75%， 186/3 237）， and the difference was statistically significant（ P＜0.05）. Conclusions A considerable proportion of primary and middle school students aged from 6 to 16 years old suffer from mental disorders in Zhenjiang. The proportion of comorbidity mental disorders is high. The prevalence of mental disorders is higher in the age stage from 12 to 16 and rural students.