Abstract: In order to understand if the apoptosis of follicular cells and oocytes exists in the buffalo fetals ovary, and if does, what is the apoptotic characteristics, ovaries was chosen from a five-month-old fetal buffalo, the apoptotic characteristics of follicular cells and oocytes was studied by paraffin section, HE staining, light microscope and terminal deoxynucleotidyl transferasemediated dUTP nick end labeling (TUNEL) technology. The results were shown that large number of apoptotic cells existed diffusedly on 5-month-old fetal ovary. Many apoptotic follicular cells and some apoptotic oocytes were distributed solely and evenly among a lot of preantrum follicles of ovary cortex. The main changes of apoptosis were cell shrinkage, nuclear condensed in histology, DNA terminal labeling appeared TUNEL positive. These results suggested that the apoptosis of ovarian follicular cells and oocytes was already existed in buffalo fetal ovary, and the apoptosis was the potential mechanism of arosing preantrum follicle atresia.