<;P>;PROBLEM TO BE SOLVED: To provide a coral artificial multiplying tool capable of being readily inserted into a gravel deposition bottom area and a sand and gravel bottom area, and stably fixed with hardly any risk of rolling with waves to be damaged or embedded once after being inserted. <;P>;SOLUTION: An inserting part 11 fixed to the lower side of a coral rearing part 3 has at least a pair of opposite or alternate wing-like barb projections 21 provided on the outer periphery of a body 13, and the distance between mutual vertically adjacent barb projections 21 is set at the diameter of branch-like coral or above. The outside lateral face 23 of the barb projections is a smooth curved surface bulged to the lower side, e.g. a contour line on the lower side of the outer lateral face of the barb projections appearing when viewed from the side is approximate to a circular arc locus with 1/2 of the distance between the mutual vertically adjacent projections as the radius; and the inside lateral face 29 of the inserting part is preferably a chevron-shaped state having a ridgeline in the central part. <;P>;COPYRIGHT: (C)2010,JPO&INPIT