Objective To establish a kind of culture system to improve %in vitro% development of Kunming mouse pronuclear embryos. Methods Mouse pronuclear embryos were obtained through superovulation, then the normal morphologic zygotes were selected and cultured in M16, CZB and KSOM respectively, or co_cultured with mice oviduct epithelia. The cell number of blastocysts obtained from in vito/in vitro were counted. Results The ratio of blastocyst formation was improved in KSOM and CZB by addition of fetal bovine serum(14.71% vs 85.71%,6.45% vs 10.81%). Co_culture system increased percentage of cleavage and blastocyst formation, and was advantageous for embryos quality and synchronized development. Conclusion Mouse pronuclear embryos developed in vitro highly in KSOM-{FBS} cocultured with oviduct epithelia.