It is very necessary to develop a real biomimetic compound coating of CaP with organic component and investigate quantitatively the effects of different bovine serum albumin (BSA) concentration on the crystallite properties of the coprecipitated CaP layer. Bioactivated Ti was immersed in Ca-P solution with different BSA contents to obtain different biomimetic coating. The coatings were analyzed with scanning electron microscopy (SEM) and X-ray diffraction (XRD). With the increase of BSA, the crystals on the coating grew more slowly but packed more closely. The preferential crystallographic direction of 002 of hydroxyapatite became less distinguishable and the crystallinity of the deposited hydroxyapatite decreased gradually. The crystallite sizes reduced with the addition of BSA proteins. Accordingly, when a certain content of BSA protein was added to the Ca-P solution, Ti surface would form a real biomimetic coating with the crystal size and crystallinity similar to the natural bone.