The Black Bengal does of Indian sub-continent generally show a noted seasonal variation during in reproductive activity. India has a good quality of Black Bengal goat populations, which has significant role in the lives of the local goat rearers. The objective of the present study is to realize the influence of seasonal variation on the serum progesterone of Black Bengal does (Capra aegagrus hircus) in two different agro-climatic regions in India. The highest assessment of temperature (42.6 ± 1.5 ºC) has been reported during the month of April or May in the season of pre monsoon in Purulia. However, the lowest assessment of temperature (8.6 ± 0.9 ºC) has been reported during the month of December or January in the season of post monsoon again in Purulia. Progesterone hormone has been analyzed in the serum samples collected once a week. It has been observed that, from January to April for both of the regions of Purulia and Nadia and the month May has the lowest serum progesterone level in Purulia (0.32 ± 0.06 ng/ml) and the serum progesterone hormone concentration stayed approximately the same from January to March in Purulia as similar to Nadia. However, the serum progesterone reached to its peak level in November in both the region Purulia (4.52 ± 0.28ng/ml) and Nadia (5.55 ± 0.18 ng/ml) respectively. It can also be presume that the early months of the post monsoon season may be taken as an alternate breeding seasons for the Black Bengal breeds.