To provide particles for water disinfection which are hard to be suspended and are hard to be diffused in water which is suitable for use of disinfecting water and which are capable of developing disinfection effect fully and method of producing the same.Particles for water disinfection in which silver is coated on a garnet surface or a particle surface whose main ingredient is garnet are used. When said particles are used, preferable embodiment of silver is that the granular lumps of silver are carried continuously and discontinuously forming a group on a garnet surface as shown in SEM photographs of FIG. 4.Effective production method of such particles can be conducted by the electroless plating method in which garnet particles are immersed in a mixed solution composed of reducing solution in which at least any one of potassium sodium tartarate, glucose, or acetardehyde as a reducing agent is dissolved in water, silver nitrate solution, and ammonium solution.