Abstract: To investigate the effects of testicular abstract (TA) from adult mice testes, epidermal growth factor (EGF) and Estradiol-17β (E2) on the survival and proliferation of mouse spermatogonial stem cells (SSCs) in vitro. The seminiferous epithelium of 8-day-old mouse was dissociated with collagenase-trypsin digestion. SSCs were enriched by differential plating and seeded on STO feeder layers in a compound media containing varied concentrations of TA, EGF and E2. The survival and proliferation of SSCs were investigated. The results showed that no significant difference was observed between the average survival times of SSCs in experiment groups and that in control groups after adding with the three factors. However, the survival times of SSCs in groups containing 20~40 ng/ml EGF and 10~100 pg/ml E2 were obviously extended, and distinct proliferation activities of SSCs were observed during a relatively long period. The results indicate that EGF of 20~40 ng/ml and E2 of 10~100 pg/ml were beneficial to the maintenance of mouse SSCs.