It is well known that unidentified factors in sera, hormones and growth factors promote the proliferation of granulosa cells and nuclear maturation of bovine COCs in vitro. Attemps had been developed the simple composition of culture media and similar system to in vivo conditions has been applied. In the present study, we investigated the effect of TGF-${eta}$ on in vitro maturation and in vitro development of Hanwoo COCs. When the COCs were matured in TCM 199 containing 0.1, 1 or 10 ng/ml TGF-${eta}$ for 24 hrs, metaphaseⅡ of COCs were obtained 95.8%, 100% of matured COCs, respectively and there were no differences among the concentrations of TGF-${eta}$. Matured COCs with TGF-${eta}$ cultured in maturation medium after in vitro fertilization, developmental rate to blastocyst were 0~0.8%. Matured COCs with TGF-${eta}$ were cultured in TCM 199+10% FBS, 0.8% BSA, 0.1% PVA, blastocyst formation were showed in 12.4%, 12.8%, 8.5% of those and cultured in IVMD or IVD without serum were 38.4%, 34.8%, respectively. There were significant differences among the media (P<0.05). TGF-${eta}$ is available for i vitro maturation of bovine COCs, but further investigation would be need for finding the synergistic autocrine/paracrine fashion of other growth factors in early bovine development.