The present investigation was undertaken to study various reproductive traits like age at puberty, oestrous behaviour, oestrus period, length of the oestrous cycle, intensity of oestrus, duration of oestrus, gestation period, parturition behaviour, status of calf and characteristics of foetal membranes in Mithun. It also included the study of biometrics of female genital organ and to ascertain the serum biochemical constituents like glucose, total protein, cholesterol, calcium and inorganic phosphorus, and hormones like FSH, LH, Estradiol-17¿ and progesterone on every alternate day during the oestrous cycle in female Mithun.