The objective of this study was to determine effects of different culture media. Preantral follicles were mechanically extracted from bovine ovaries and cultured for 16 days in tissue culture medium (TCM)-199, DMEM or alpha-minimal essential medium ($alpha$-MEM) + 10% FBS + 0.1 mg/ml sodium pyruvate + 100 mIU/ml FSH. The collected primary follicles from ovary were higher than the primary and secondary follicles. The survival rates of the follicles in TCM-199 were significantly higher (p<0.05) than those in DMEM and $alpha$-MEM. The diameter of the follicles progressively increased during 12 days of culture. The maximum size ($139.1{pm}5.4;{mu}m$) reached on Day 12 of the in vitro culture and decreased on Day 16. These results suggest that in a culture of bovine preantral follicles, TCM-199 is an optimal medium and a longer-term culture of preantral follicles (>12 days) may be needed to form antra.