In order to study the level of the selected elements(Ca, Zn and Cd, etc.) in milk and their interrelationships with milk protein, raw milk samples in the vicinity of Seoul and market milk samples were collected in the summer, winter and early spring. The average Ca and Zn content of milk from different areas and different products varied between 0.06∼0.13% and 2∼5ppm, respectively, and the Cu content is below 0.lppm. Cd(regarded as a toxic element) content in milk is not detected and the Hg content is below the detection limit of AAS instrument in the milk produced in Korea. The interrelationship of these elements with milk components(specially with casein) is also studied. Generally, inorganic elements(Ca, Mg and Zn) are contained in the portion of casein and whey. The fraction of α_s -casein contains higher Ca amounts than that of β- or k-casein does, but we have not found out that these elements are combined with milk component or not.