Abstract: Objective：To investigate the effect of Follicle Stimulation Hormone （FSH） and pentanoic acid estradiol on the mouse oocytes in vitro maturation, and the capacity of in vitro fertilization and merogenesis. Methods：The female Kuming mice were conducted superovulation. Immature oocytes were collected from those ovaries. Those immature oocytes were classified as six groups: matured for 24 h in the basal culture fluid without hormone as control; and the culture fluid added 10 and 50 IU/mL FSH; and the culture fluid added 1, 10, 100 mg/L pentanoic acid estradiol, The status of oocytematuration was observed, those matured oocytes were then inseminated in-vitro. The capability of fertilization was observed, and the inseminated oocytes were cultured for another 48-72 hours. The cleavage rate was compared at last. Results：① Compared with control, all treated groups had similar rates of undergoing GVBD, MII and cleavage （P＞0.05）. ②The fertilization rates in those groups treated with 10, 50 IU/mL FSH and 10 mg/L pentanoic acid estradiol were 41.18％，40％ and 42.86% respectively. Those rates were all higher than that in control group（19.44％） （P＜0.05）. Compared with control, two groups treated with 1 and 100 mg/L pentanoic acid estradiol had similar cleavage rate and fertilization rate（P＞0.05）. ③The percentages of GVBD, MII and cleavage in groups treated with FSH and pentanoic acid estradiol of different concentrations were similar （P＞0.05）. Conclusions：The addition of 10 and 50 IU/mL FSH or 10 mg/L pentanoic acid estradiol in the mouse IVM culture solution could promote the mature of mouse oocyte cytoplasm，and increase the fertilization rate.

Key words: Oocytes, Cells, cultured, Cell culture techniques, Fertilization in vitro, Follicle stimulating hormone, Estradiol