Abstract: A pathogenic bacteria of CH -108 st rain is isolated from the hole disease of the Triony x sinensis .I t is ident ified as Aeromonas hydrophi la by the bacteriological method .The backinoculation test indicated tha t or iginal symptome can be observed by inject ing the pathogens into the healthy ones .The drug sensitivity test showed tha t the CH - 108 st rain is moderate se nsi tir ity to str eptemyclnum and ciprofloxacin .Immune inoculat ion using kil led CH -108 st rain can prevent hole disease effect ively .