This study was designed to evaluate the effects of nitric oxide scavenger (hemoglobin) and inhibitor (L-nitro-L-arginine methyl ester; L-NAME) with or without cumulus cell on the development of bovine IVM/IVF embryos. When CR_1aa medium were supplemented with different dosage (lug/m, 5ug/m and 10ug/ml) of hemoglobin at 48hrs for in vitro culture, the proportion of embryos developing beyond morulae stage in 0, 1ug/ml and 5ug/ml with or without cumulus cell were 23.8%, 33.3 % and 26.8%, and 39.5%, 54.8% and 48.8%, respectively. There was a significantly difference the developmental rate of 1ug/ml hemoglobin intact cumulus cells to any other groups (P<0.05). On the other hand, when added to hemoglobin at 96 hrs, 1 ug/ml hemoglobin with cumulus cell group was significantly increased the percentage of developing into morulae and blastocysts to any other groups (P<0.05), and similar trend that of added at 48hrs. The overall means of the percentage of developing into morulae and blstocysts in 1ug/ml hemoglobin group was significantly increased than those of any other groups (P<0.05) and cumulus co-culture with hemoglobin was increased the in vitro developing rate of IVM/IVF embryos. In CR_1aa medium treated with L-NAME 0, 10, 50 and 100mM, the developmental rate of morula plus blastocysts were 55.6%, 64.9%, 58.8% and 66.7%, respectively. The L-NAME did not affect the developmental rate and the cell numbers of blastocysts in all treated groups. These results indicate that hemoglobin and cumulus co-culture can increase the proportion of embryos that developed into morulae and blastocysts, but cell numbers of blastocysts were not affect in all groups.