Objective To explore the effects of heroin dependence on the epidermal growth factor(EGF), β-endrophin(β-EP) positive cells in the testis of rats and the changes of the serum levels of follicle-stimulating hormone (FSH), comprehend the possible functions of EGF, β-EP and FSH during heroin dependence. Methods Immunohistochemical SABC method, radioimmunoassay (RIA), counting the number of cells and image analysis were used in the studies. Results 1. Compared with the normal control group (NCG) and saline control group (SCG), the number of EGF positive cells decreased ( P<0.05 ), the intensity of staining stepped up gradually with the passage of time during dependence. The result of image analysis showed that the mean gray degree of the EGF positive cells decreased. 2. The number of β-EP positive cells in heroin dependence group(HDG) were less than that in NCG and SCG ( EM>P/EM><0.05 ).The immunohistochemical staining intensity of β-EP positive cells in testis decreased as compared with SCG and NCG and the means of gray degree increased gradually during heroin dependence (EM>P/EM><0.05). 3. The RIA result showed that the level of FSH was the lowest on the 10th day and then elevated as compared with SCG and NCG on the 17th day during heroin dependence. Conclusion During heroin dependence, the secretion function of the testis EGF positive cells was enhanced while the function the β-EP positive cells was weakened. The number of EGF,β-EP positive cells decreased markedly in testis. The secretory volume of FSH changes. The above findings indicated that testis ma