Abstract: Objective To know the disinfection effect of chlorine dioxide on surface water in order to provide disinfection basis of drinking water for actualuse,especially for the outdoor sworking army.Methods To study on the change of turbidity,critical odor value of surface water before and after disinfection by chlorine dioxide.To compare the ability of removing rate of odor between chlorine dioxide and sodium dichloroisocyanurate.The efficacy of chlorine dioxide to kill total bacteria count,E.coli group and bacteriophage f₂ in surface water was measured.Results Chlorine dioxide could reduce the odor and turbidity of surface water remarkably,the removing rate of odor was 50%-80%.It was better than that of Sodium dichloroisocyanurate when the water contains Hydroxybenzene.Ten mg/L chlorine dioxide with a contacting time of 30 minute could kill total bacteria count and E.coli group in the clearer river water and like water,and more than 99.9% was killed in the river water which was polluted badly.After disinfected by chlorine dioxide,the amount of E.coli group in water can be reduce to the standard for drinking water(<3/L).When the water taking from like contaminated bacteriophage f₂ with 1.414×104 pfu/ml.Contacting 1 hour with 1mg/L chlorine dioxide,the bacter iophage f₂ could be killed more than 99.9%.Conclusion Chlorine dioxide could reduce the odor and turbidity of surface water remarkably.After disinfected by chlor ine dioxide,the amount of bacteria in water can be reduced to the standard for drinking water.