Objective To have knowledge about the incidence of mandibular third molar impaction and pericoronitis in college students and to provide a basis for taking corresponding preventive measures.Method Oral examination was conducted for 1 726higher vocational college students

the incidence and treatment of pericoronitis were comprehended by means of questionnaire survey.Results There were 547cases who had mandibular third molar impaction with a detection rate of 31.69%;there were 202cases of male and 345cases of female with a respective detection rate of 28.61%and 33.82%

the detection rate in female students was higher than male students;impaction types were mainly mesioangular impaction

followed by vertical impaction

with a respective percentage of 44.69% and 38.71%.Incidence rate of pericoronitis of impacted tooth was 92.56%;visiting rate of pericoronitis in male and female students were 36.02% and 62.42% respectively

which in female students was higher than male students（p<0.05）.Conclusion Rate of mandibular third molar impaction and incidence rate of pericoronitis in college students were relatively high.Institute of higher education should strengthen oral health education to reduce the incidence rate of pericoronitis and improve the quality of oral health in college students.