The object of the study was the Far Eastern forest cat’s heart. Morphometric parameters were calculated with the help of a mler and calipers. The measurement parameters were the length of the heart, from the point of origin of the aorta to the apex; width, distance between lateral surfaces of the heart at the level of the base of the ventricles; and the thickness from forward and back cut, also at the level of the base of the ventricles. Using the formula, we calculated cardiac index basing on the index the shape of a heart was determined. Index of 65 % corresponds to a conical form, 65-75 % corresponds to ellipsoid; more than 75 % corresponds to spherical. After the measurements the main components of the heart were defined, i.e. the number, location, size and individual characteristics of the internal structures such as scallop muscle, papillary muscle, trabeculae, the stmcture of the valve apparatus. The length of the papillary muscle was determined by the distance from the middle of the base to the top width and cross-sectional dimension at the middle of it. According to calculations, the heart of Far Eastern forest cat can be of two types: conical (cardiac index to 65 %) - one case; elliptical (65-75%) - three cases. The mass of the heart in animals was 27,41 g, thickness of the right ventricle was 2,54 mm, left was 7,51 mm; the thickness of the wall of the right atrium was 0,52 mm, left was 0,62 mm. An important feature of heart of Far Eastern forest cat, its difference is in ears fibrillation in size. The left atrial appendage is 1,67±0,628 cm in length and of 1,51±0,44 cm in width. Flis right ear is 3,07±0,27 cm in length and 1,81±0,56 cm wide, has a stretched oval shape.