作者于1982年9月至1984牟5月对205名大学生感染人体蠕形螨的变化情况进行了四次观察。四次检查的感染率在9.76～23.41%之间;累计阳性者85人。感染度较低。约5%的感染者面部有轻度皮肤病变。各次检查之间以及男女生之间的感染率无显著差异。但每次检查都有较多的新感染者(43～58.3%),而且阴转现象也比较明显(10～78.5%)。本文对各次检查时新检出阳性及阴转现象进行了讨论。 The author observed four changes in 205 college students infected with Demodex from September 1982 to May 1984. The infection rates of the four tests ranged from 9.76% to 23.41%; 85 were positive. Infection is low. About 5% of infected persons have mild skin lesions on the face. There was no significant difference in infection rates between exams and between boys and girls. However, each examination had more new infections (43 ~ 58.3%), and the phenomenon of overcast was also obvious (10 ~ 78.5%). This article examines newly detected positive and negative phenomena at each examination.