To study the effect of cadmium on the apoptosis of spermatogenic cells of rat testis and the protective effect of zinc against it. 24 Wistar male rats were divided into 3 groups (cadmium, cadmium and zinc, and control rats). Rats were injected with low-dose CdCl2 (2 mg/kgBW), zinc acetate(ZnAc, 15 mg/kgBW) before and after injected with low-dose CdCl2 and ZnAc(50 mg/kgBW). The control rats were injected with same-dose of 0.9% NaCl. After 7 days, the apoptosis of spermatogenic cells was studied with in situ nick translation(ISNT) technique. Compared with control group, the number of apoptosis spermategenic cells was obviously increased in cadmium group(P < 0.01, t = 3.87), but it was not significantly different in cadmium and zinc rats. Cadmium treatment could accelerate testis apoptosis. Zinc could proven it.