This study was performed to describe the morphology of buffaloes oocyte organelles during in vitro maturation and to identify the differences in selected transcripts abundance of buffalo oocytes in relation to oocytes¿ quality. In the 1st experiment, cumulus-oocyte complexes (COCs) were aspirated from antral follicles. Oocytes were evaluated and classified as good oocytes and denuded. Good-quality oocytes were selected for in vitro maturation (IVM) according to the adopted procedure. A total number of 10 good and 10 denuded oocytes were selected and prepared for ultra-structure examination using transmission electron microscopy. A total number of 3 in vitro matured oocytes and 3 oocytes failed to reach maturation are prepared to study the ultra-structure. In conclusion, the quality of oocytes is a key factor in the determination of the earliest steps of embryo development. In addition, the quality of oocytes affects the expressions of genes responsible for early embryonic developmental competence.