In order to investigate the effects of age on androgen receptor (AR) in testes and epididymides of mandarin voles ( Lasiopodomys mandarinus
), the expression of AR from five age groups [postnatal 1(neonatal), 10, 25, 45 and 60 days (adult) of age] was examined using immunohistochemistry method. The results were as follows: ① There was AR expression in leydig cells in neonatal voles and the expression of AR decreased at postnatal 10 days and 25days. AR expression reached its peak at postnatal 45 days and then decreased in adults（P<0.05）. ② The positive expression of AR in myoid cells was found from neonatal to adult. The positive expression of AR was unchanged at postnatal 1 day and postnatal 10 days, but decreased at postnatal 25 days, reaching its highest level at postnatal 45 days and then decreased in adults (P<0.05). ③ The positive expression of AR in prospermatogonia was weak in neonatal voles. There was no expression of AR in spermatogonia at postnatal 10 days. There was AR expression in spermatoon at postnatal 25 days, while in spermatocyte and some spermatoon at postnatal 45days. The positive expression of AR in spermatogonia, spermatoon and sperm was also found in adults. ④ The positive expression of AR in sertoli cells was found in adults, but there were few expressions of ARs at other ages. ⑤ The positive cells of ARs were both detected in epithelium cells and stroma cells of epididymides. These results suggest that AR expressiones in leydig cells, myoid cells and spermatogenic cells change significantly with mandarin vole’s individual development. Androgen facilitates leydig cells differentiation during puberty, and myoid cells play an important role during spermatogenesis. Androgen may regulate function of epididymises.