The purpose of the research was to the influence of goat follicular fluid (GFF) with different levels in maturation medium in vitro on cumulus expansion and transformation of goat oocyte nucleus. The results of this study showed that cumulus cell expansion was related to the higher level of different GFF in maturation medium TCM-199. Cumulus cell expansion, and increased nucleus transformation occurs at level of 10% and decreased medium without GFF. This suggests that cumulus expansion and nucleus transformation decreases, because the need of oocyte is not supported by hormones and nutrients in the maturation medium. Key words: GFF, TCM-199, cumulus expansion and maturation of the nucleu
