The aim of this study was to investigate the effects of Oxytropis glabra DC. poisoning on α-mannosidase（AMA） in rat ovary, and further reveal the toxicity mechanism of O. glabra DC. 72 female rats were randomly andequally divided into 4 groups（the control group and experimental group Ⅰ, Ⅱ, Ⅲ）, different doses of dried plant of O. glabra DC. were mixed with the feeds in the three experimental groups. The rats consumed the forages freely un-til typical symptoms were observed. 2 rats were selected randomly from each group every week respectively, the ova-ry was collected and the contents of AMA and its m RNA expression in different encephalic regions were measured.In 63 days test period, it was found that AMA in golgi and lysosomal expressed in ovary of all experimental groups,O. glabra DC. inhibited the expression of ovary AMA1 and AMA2 m RNA, and the difference was significant. Thedifference were not significant in experimental group Ⅰ and control group（P＞0.05）, the content of AMA and expres-sion of AMA1 m RNA in experimental group Ⅱ, Ⅲ were very significant lower than in control group（P＜0.01）, theexpression of AMA2 m RNA in experimental group Ⅲ were significant lower than control group（P＜0.05）, but the dif-ference of expression of AMA2 m RNA were not significant between experimental group Ⅱ and control group（P＞0.05）. The results showed that O. glabra DC. has remarkable effects on content and transcriptional expression ofAMA in rat ovary, in a time-effect as a dose-effect relationship.