This study was aimed to measure and determine the size of some body parts of the muscovy duck (Carina moschata) and their relationship with body weight. The research was be carried out for two months from August to September 2023 in local Intensive Muscovy Duck farm, Kademangan area, Blitar, East Java. The research material use were 60 muscovy ducks (unsexed), aged 3 weeks old, and reared in intensive farming system. This study used experiment quantitative methods (measurement). Muscovy duck sampling was carried out by random sampling. The variables observed were body weight, beak length, beak width, head length, head circumference, neck length, neck circumference, wing length, back length, chest length, chest width, shank length, shank circumference, and leg membrane width. Measurements were made on each individual using a measuring tape. The data obtained were tabulated and analyzed using normality test, correlation test and regression test. The results showed that there is a positive correlation between the morphological dimensions of livestock, including membrane width, shank length, beak width, wing length, head width, head length, neck length, shank circumference, beak length, breast length, breast width, neck circumference, back length, and body weight. And the length of the back has the largest contribution of 54% to the body weight of muscovy ducks (Carina moschata) aged 3 weeks old.