Provided herein is a method for preparation of soft calcium Hydroxyapatite including: mixing a salt of calcium ion with a polymer to obtain a solution, addition of a salt of phosphate ion with the solution thus obtained to obtain aqueous calcium Hydroxyapatite, freeze drying to obtain soft calcium Hydroxyapatite (HA). The soft calcium Hydroxyapatite is a stable compound, which is sponge like with cellular matrix. When it is filled into a cavity of bone, it makes a wide area contact with bony cage around.