In the present study, effects of concentration of cryoprotectant solutions on the nuclear maturation of vitrifiedthawed porcine oocytes were examined. Oocytes were cultured in TCM-199 medium supplemented with 5% FBS at C in 5% and air. The percentage of monospermy in the toxicity group and vitrification group (22.0 3.0% and 31.5 3.5%) was decreased compared with that of the control group (44.0 4.0%). The percentage of in vitro development to blastocyst in the toxicity group and vitrification group (12.0 2.5% and 14.8 2.8%) was decreased compared with that of the control group (28.0 3.0%, p<0.05). The survival and in vitro developmental rate of oocytes vitrification-thawed with EDS and EDT + TCM-199 medium supplemented with 0.1% PVA were 46.3 3.0%, 54.5 3.8% and 14.8 2.5%, 16.4 2.7%, respectively. This results were lower than the control group (28.0 3.5%). The in vitro developmental rate of embryos vitrified with EDS and EDT supplemented PVA did not have a significant difference. The survival and in vitro developmental rate of vitrified-thawed morula and blastocyst embryos were 44.2 3.5%, 17.3 3.0% and 48.1 4.2%, 18.5 3.5%, respectively. Vitrified morulae and blastcyst embryos had a lower survival and developmental rates than their control counterparts.