In the present study, effects of concentration of cryoprotectant solutions on the nuclear maturation of vitrifiedthawed bovine oocytes were examined. Also, the developmental capacity of vitrified-thawed immature oocytes following ICSI was investigated. Oocytes were cultured in TCM-199 medium supplemented with 5% FBS at $38^{circ}$C in 5% $CO_2$ and air. The in vitro maturation rate of vitrified oocytes was 24.5 ${pm}$ 4.2%. The in vitro maturation rate of vitrified oocytes was lower than that of the control (72.0 ${pm}$ 3.5%, p<0.05). The in vitro maturation rate of vitrified${sim}$thawed oocytes incubated in TCM-199 medium supplemented with 1.0${sim}$5.0 ug CB were 26.7 ${pm}$ 3.2%, 35.7 ${pm}$ 3.2%, 54.0 ${pm}$ 3.0%, 42.5 ${pm}$ 3.6%, respectively. The in vitro maturation rate (57.0 ${pm}$ 3.0%) of the vitrified-thawed oocytes treated with 3.0 ${mu}$g CB for 20 min was the highest of all vitrification groups, although the maturation rate were significantly (p<0.05) lower than those of fresh oocytes. The in vitro maturation rates of the vitrified-thawed (with EDS and EDT) oocytes were 53.8 ${pm}$ 3.4%, 51.1 ${pm}$ 3.5%, respectively. This results were lower than the control group (72.0 ${pm}$ 3.0%). The in vitro developmental rates of the vitrified-thawed oocytes following ICSI were 28.6 ${pm}$ 4.5%, 25.6 ${pm}$ 4.3%, respectively. This results were lower than the control group (40.0 ${pm}$ 4.0%).