<；P>；PROBLEM TO BE SOLVED: To provide a method for growing bivalves, which stably promotes groundings of larvae and young shellfishes 5 of bivalves, such as, clams for a longer period of time, bottom quality improving base materials 2 and a method for improving the bottom qualities. <；P>；SOLUTION: The method for growing bivalves includes the step of: scattering a large number of substantially granular bottom quality improving base materials 2 that sink in water, have a lower bulk specific gravity than that of sand 1 and a larger volume than that of the sand 1 on a water bottom 3 holding the sand 1 in the habitat area of bivalves, such as clams； and promoting groundings of larvae and young shellfishes 5 of clams, and the like, by a large number of the bottom quality improving base materials 2 that do not move much, even by normal waves and substantially maintain a water bottom surface layer part 4, even if the bottom materials are liquefied by strong waves. <；P>；COPYRIGHT: (C)2009,JPO&INPIT
