PURPOSE: To produce the osteoblast-producing substance without adding serum, a cell growth factor, etc., to a culture medium by culturing the osteoblast on a carrier comprising hydroxyapatite adsorbing a polysaccharide therein.

CONSTITUTION: The osteoblast is cultured on a carrier comprising hydroxyapatite adsorbing a polysaccharide such as starch therein. The carrier can stimulate the growth factor receptor of the osteoblast, culture the osteoblast without adding serum, etc., to the culture medium, and facilitate the separation and purification of the osteoblast-producing substance. The osteoblast such as an osteogenetic cell strain: MC3T3-E1 cell can well produces TGF-β, etc.