PROBLEM TO BE SOLVED: To provide a completely new method for producing seaweed seeds and seedlings, which is capable of efficiently raising embryos of various seaweeds as seeds and seedlings. SOLUTION: This method for producing the seaweed seeds and seedlings comprises a process A of preparing a plurality of small block-like seaweed raising substrates which have substantially specific gravity the same as that of seawater and recessed parts on the upper surface, and sowing seaweed embryos on the recessed parts, a process B of arranging the substrates in plane and culturing until the embryos become immatures, a process C of moving the substrates after culturing directly to a water tank in which seawater is put, and culturing the embryo while stirring seawater in the water tank by seawater injection and aeration so as to keep a floating condition of each immature alone, and a process D of attaching the substrates after culturing to a substrate fixing means at certain intervals, and transplanting seaweed seeds and seedlings for seaweed bed creation or putting out offshore seaweed seeds and seedlings for sea level cultivation. The material of the substrate is preferably an ABS resin, and the substrate fixing means is preferably a rope or plastic-made block. COPYRIGHT: (C)2007,JPO&INPIT
