An antibacterial material for water comprising a carrier containing an antibacterial agent and a fabric surrounding it is disclosed. When this antibacterial material for water is placed in water, microorganisms living in the water would pass through the fabric and approach the carrier, so that they are attacked by the antibacterial agent contained therein and die. On the other hand, contaminants and slime in the water cannot approach the carrier since they are filtered off by the fabric. Therefore the surface of the carrier is hardly coated with contaminants or slime and kept in an exposed state. As a result, the antibiotic effect of the antibacterial material on the water can be maintained for a long period of time.