The present work was planned to study the influence of the reproductive status, BCS as, well as, season variation on the follicular population of buffalo-cows. In addition to getting up good quality oocytes, and to formulate the best additives used for in-vitro maturation of the oocytes collected from different size ovarian follicles of buffalo cows. A total number of 458 ovaries were collected from 229 slaughtered buffalo-cows within 30 minutes after slaughtering and transported to the lab within 2-3 hr. The body condition score of the investigated buffalo-cows, the morphological qualification of the ovaries, estimation of estradiol, progesterone and testosterone levels of the follicular fluid and plasma were investigated. Moreover, the effects of some additives as sire serum and granulosa cells used for in-vitro maturation of the buffalo oocytes were also studied. The results of this study revealed the following: 1. It was found that the buffalo-ovaries bearing about 3.22±0.17 and 3.11±0.15 visible follicles for right and left ovaries respectively. The high number of this follicles (2.43±0.16 and 2.44±0.15), were <5mm in the right and left ovaries, respectively. Moreover, the follicular population was significantly increased in ovary bearing CL compared to the opposite one. 2. The presence of large follicles >8 mm on one ovary, significantly decreased the number of medium size follicles (5-8 mm), while it showed no significant effect on the number of small follicles (<5) on the ovary of buffalo cows. 3. Increasing the BCS of buffalo-cows found to increase the number of large follicles (>8 mm) as well as the ovarian weight and width. 4. There was no significant variation in the follicular population, ovarian dimensions or ovarian weight among different seasons. 5. The animals with mature GF or CL III showed a higher levels of estradiol and progesterone, respectively, in winter and spring than summer and autumn. 6. There was an increase in the estradiol concentration in the follicular fluid with increasing the follicular size even in the luteal follicle from 509±35.6 pg/ml in follicles <5mm to 845±20.0 pg/ml in large follicles (>8 mm). Whereas, progesterone and testosterone were decreased from 14.5±0.40 and 10.12±1.05 ng/ml in small follicles (<5 mm) to 11.62±1.31 and 4.52±0.32 ng/ml in large follicles (>8 mm), respectively. 7. The present results cited that observations of the Egyptian buffaloes ovaries and the increase in the plasma estradiol level confirmed the wavy pattern of follicular growth as large follicles were found accompanied the CH and CL III. 8. 724 oocytes were aspirated from 350 ovaries (2.07 oocytes/ovary), 513 of them were usable (1.46 usable oocytes/ovary). Moreover, 143 oocytes only (0.41 oocyte/ovary) were aspirated from large follicles >5 mm, 105 of them (0.3 oocyte / ovary) were usable, while 581 oocytes (1.66 oocytes/ovary) were aspirated from small follicles <5 mm, 408 of them (1.16 oocytes/ovary) were usable. 9. There was a significant more oocytes and usable one collected from large follicles (>5 mm) during winter than other seasons. 10. The highest maturation rate (55 and 79.17%) for oocytes collected from small <5 mm and large follicles respectively, were recorded in oocytes cultivated in TCM-199 with 10% SS. While the maturation rate of the oocytes cultivated in TCM-199 supplemented with granulosa cells (2x106 cells/ml) was 34.13 and 47.37% respectively. 11. There was a higher steroids levels in postmaturaiton media supplemented with granulosa cells than the nonsupplemented ones. 12. There was a non significant effect of follicular size on the maturation rate of buffalo oocytes.