PROBLEM TO BE SOLVED: To provide a calcium-phosphorylated starch complex having the following features: water-soluble at pH in the neutral region, having excellent solubility even in pulverized state, and excellent in absorbability and utility in vivo and useful for preventing and treating various bone diseases such as osteoporosis, fracture, rheumatism, arthritis and lumbago when it is compounded into a medicine, a food or a feed. SOLUTION: The calcium-phosphorylated starch complex is prepared by mixing, an inorganic calcium salt and/or an organic calcium salt, an inorganic phosphoric acid salt and a phosphorylated starch, and adjusting the pH value of the resultant mixture at >=5.5 to form a complex of calcium and phosphorylated starch.
