Objective To study the effects of mineral oil covered M2 culture medium droplet culture, M16 droplet culture, and dimethyl sulfoxide (DMSO) on the morphology and survival rates of mouse oocytes during the release from diplotene arrest. Methods Oocytes were randomly divided into 3 groups and individually cultured for 4 h in M2 covered with mineral oil, M16 covered with mineral oil, and/or M16 only to cause germinal vesicle breakdown (GVBD). The morphological changes and survival rates of oocytes in each group were observed under the microscope. Oocytes were randomly divided into 3 groups and cultured in the medium with 0％, 1％, and 2％ DMSO. The effect of DMSO on oocytes was also observed during the release from diplotene arrest. Results The survival rates of oocytes in M2 covered with mineral oil were higher than those in M16 (P ＜ 0.05). There was no statistical difference with respect to release of mouse oocytes from diplotene arrest between the oocytes in M2 covered with mineral oil and oocytes in M16. The shape of oocytes in M2 with mineral oil was better than that of oocytes in M16. The effect of DMSO on the survival rate of oocytes was similar in the medium with 0％, 1％ and 2％DMSO. But the effect of 2％ DMSO on the release of oocytes was statistically significant (P ＜ 0.01). Conclusion During the release of mouse oocytes from diplotene arrest, oocytes in M2 covered with mineral oil have much better morphology and higher survival rate than those in M16. DMSO (0％, 1％ and 2％) has no effect on the survival rate of oocytes. However, 2％ DMSO is more effective in promoting the release of mouse oocytes from diplotene arrest.