Abstract: 32 Kunming male mice were randomly divided into 4 groups,which were fed with DHEA of 0 mg/kg （control group）, 20 mg/kg（low-dose group）, 40 mg/kg （medium-dose group） and 60 mg/kg （high-dose group） every day. The experiment lasted for 52 days. The mice in every group were killed on the 42 day-old and 72 day-old respectively. The testis was picked to make into paraffin sections and observe in microscope after HE staining. The results showed that the cross-section of seminiferous tubules deformed on 42 day-old and the number of spermatogenic cells and mature spermatozoa in each period all reduced in medium-dose group and high-dose group, compared with control group. In high-dose group, the hierarchy of spermatogenic cell in seminiferous tubule basically disappeared, bigger lacuna appeared and interstitium changed to different extent. On 72 day-old, the cross-section of seminiferous tubules deformed, basement membrane became thin accompanied by fracture and damaged extent of interstitium increased in medium-dose group and high-dose group. Abnormal sperms were found in medium dose group. In high-dose group, central blank area in seminiferous tubule was enlarged and mature sperm lacked. The results suggested that medium-dose and high-dose of DHEA had obvious toxic effects on the structure development of testieular tissue in growing mice.