Abstract: Microencapsulated milk calcium (MMC) was a kind of microcapsule of the milk mineral salts, which were obtained by selectively removing part of the protein and lactose in whey. MMC was a new type of efficient calcium supplement. In this paper, the structure and properties of an import MMC product were investigated by means of scanning electron microscopy, fourier transforms infrared (FT-IR) spectroscopy, X-ray diffraction, X-ray fluorescence and some other instruments. Results showed that the surface of MMC particles was concavoconvex and the particle diameter was unequal from 2 to 100 micron;Main component of MMC was phosphoric acid calcium salt;Thereinto, ash 78.5%⁷8.9%;protein 1.93%;MMC could be dissolved in acidic or highly acidic solution.