PROBLEM TO BE SOLVED: To obtain an antibacterial agent for adhesive marine bacteria, harmless to the environment and human body and having excellent sustained antibacterial power, and to provide a method for the production of the agent.SOLUTION: The antibacterial agent for adhesive marine bacteria contains at least one kind of substance selected from histidine-silver complex, methionine-silver complex, imidazole-silver complex and cysteine. This invention further provides an antibacterial agent for adhesive marine bacteria produced by supporting the above antibacterial agent on a carrier, and a coating material composition containing the antibacterial agent for adhesive marine bacteria and preventing the adhesion of marine organisms.COPYRIGHT: (C)2005,JPO&NCIPI【課題】環境や人体に無害で、持続的抗菌性に優れた海洋付着菌用抗菌剤およびその製造方法を提供する。【解決手段】ヒスチジン-銀錯体、メチオニン-銀錯体、イミダゾール-銀錯体およびシステインからなる群より選択される少なくとも1種を含む、海洋付着菌用抗菌剤および該抗菌剤を担体に担持させてなる海洋付着菌用抗菌剤。さらに、前記海洋付着菌用抗菌剤を含む、水中生物付着防止用塗料組成物。【選択図】図1