The changes in lipid peroxide and nitric oxide productions, antioxidant activities (superoxide dismutase, glutathione and vitamin E) and total lipids were studied in corpora lutea and its relation to serum progesterone levels in buffalo-cows. A total of 48 corpora lutea were dissected from ovaries obtained from local abattoir and classified according to physico-anatomy to developing, fully developed and regressing corpora lutea. In regressing corpora lutea, although, the total LPO production was higher the NO production was lower than in developing or fully developed CLs. Moreover, LPO production was negatively correlated with both SOD and serum P4 levels, which were significant in fully developed or in regressing CLS. Superoxide dismutase activity and glutathione content were significantly higher in fully developed corpora lutea. SOD activity was significantly positively correlated with serum P4 levels in developing or fully developed CLs. Vitamin E content tend to be higher in regressing CL than in other stages of development of CL. However, a marked increase of total lipid content was observed in regressing CL than in developing or fully developed CL, the cholesterol levels was unchanged. It's concluded that changes in lipid peroxide and nitric oxide production and antioxidant activities is a dynamic and regulated process, which could play an important role in regulating luteal function during estrous cycle in buffalo-cows.