Objective To investigate the relationship between Demodex infection and season , sex, different parts and the infectious rate of Demodex in human faces among students of a university and to prevent diseases caused by Demodex infection.Methods The samples of Demodex were collected from sophomores in December 2006 to May 2007.Results The results showed that the infectious rate in male,31.5% in winter and 38.0% in summer respectively, higher than those in female.On the face, the highest infectious rate was on the nose.The infectious rate on the cheeks was lowest.The relationship between Demodex infection and season, sex was observed.Conclusion The infectious rate of Demodex in human faces is associated with the season and sex.