In the present study, the effect of cysteine and NT or bisphenol A (BP) on in vitro aturation (IVM) of porcine oocytes were examined. COCs was cultured in NCSU-23 medium supplement with 10% FCS which had previously been covered with mineral oil and equilibrated in a humidified atmosphere of 5% CO2 and 95% air at 38℃. The IVM rate of oocytes cultured for 48 hrs in NCSU-23 medium supplement with 0.5~10.0 mM cysteine were 34.0±3.2%, 36.0±3.5%, 48.0±3.8%, 22.0±3.2%, respectively. The IVM rate of oocytes cultured in NCSU-23 medium supplement with 0.5~5.0 mM NT for 48 hrs were 24.0±4.2%, 18.0±4.9%, 8.0±2.2%, respectively. NT affects oocyte in vitro maturation rate in a dose-dependent. This result were significantly lower than the control group. The IVM rate of oocytes cultured for 48 hrs in NCSU-23 medium supplement with 1.0 mM NT+5.0 mM cysteine (38.0±4.3%) were significantly higher than that of NT treatment. The IVM rate of oocytes cultured in NCSU-23 medium supplement with 0.05~5.0 mM BP for 48 hrs were 20.0±4.7%, 10.0±5.3%, 6.0±3.2%, respectively. The IVM rate of oocytes cultured in NCSU-23 medium supplement with BP was significantly lower cultured non supplement of BP (44.0±3.5%). BP affects porcine oocyte maturation rate in a dose-dependent manner. The IVM rate of oocytes cultured for 48 hrs in NCSU-23 medium supplement with 1.0 mM BP+5.0 mM cysteine (32.0±3.2%) were increased than that of BP treatment.