Objective: To analyze the expression and significance of glial cell-derived neurotrophic factor receptor a1 gene (GFRα1) in the regeneration of spermatogenesis in mice. Methods: Adult Kunming mice were given intraperitoneally 2 doses of busulfan (10 mg/kg) 24 days apart to establish the spermatogenesis regeneration model. Testes were harvested at weeks 1, 2, 3, 4, 6, 8 and 10 after the second injection. The spermatogenesis regeneration was observed by light and electron microscopy and the GFRα1 mRNA measured by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization. Results: The expression of GFRal mRNA increased significantly at week 1 and reached its peak at week 2 after the second injection (P<0.01, vs the control); the expression reduced significantly at week 3 and reached its nadir at week 4 (P<0.01, vs the control); then it increased gradually and returned to the normal level at week 10. GFRal mRNA was mainly expressed by the undifferentiated spermato Methods: Adult Kunming mice were given intraperitoneally 2 doses of busulfan (10 mg / kg) 24 days apart (GFRα1) in the regeneration of spermatogenesis in mice to establish the spermatogenesis regeneration model. Testes were harvested at weeks 1, 2, 3, 4, 6, 8 and 10 after the second injection. The spermatogenesis regeneration was observed by light and electron microscopy and the GFRα1 mRNA measured by semi-quantitative reverse Results: The expression of GFRal mRNA increased significantly at week 1 and reached its peak at week 2 after the second injection (P <0.01 vs vs control); the reduced expression of GFRal mRNA increased significantly at week 1 and reached its peak at week 2 after the second injection significantly at week 3 and reached its nadir at week 4 (P <0.01 vs vs control); then it increased gradually and returned to the normal level at week 10. GFRal mRNA was primarily expressed by the undiff erentiated spermato