Abstract: There is provided a structure of artificial bone for use in implanting or grafting bone comprising; a sintered body of calcium phosphate compounds; and hollowed minute tubes in said sintered body, having very small diameter, and extending along with a direction of Haversian canal extension of live organism, so as to produce two dimensional close-packed structure in said body, in form of cubic or hexagonal arrangement. The arrangement has in the sintered body of calcium phosphate compounds; hollowed minute tubes having a diameter of 0.1 to 2.0 mm, and the major portions thereof extending along with a direction of the Haversian canal extension, and producing a two dimensional close packed arrangement in said body against the face vertical to said direction, and being arranged with a separation, distance of 1.0 to 5.0 mm. The structure has preferably really spherical pores having diameter of 50 to 600 micrometer, and the porosity thereof being 0.5 to 40 percent.