Abstract: Based on daily precipitation date, socio-economic data,GIS data and historical disaster data,the authors analyzed the fatalness of disaster-inducing factors,sensitivity of disaster-forming environments and vulnerability of disaster-bearing bodies by using GIS method.Then the model of risking valuation was built with the method of weighted synthesis evaluation and natural breakpoint classification method of GIS Risk zoning charts of flood and waterlog in Heilongjiang province was painted and was divided into five hierarchies：high,less high,medium,less low and low.The results showed that risk of flood and waterlog presented high in the east and west areas but low in the north and south.Most area of Songnen plain,north and south of Sanjiang plain and the central of Hegang belonged to high risking zone,especially north-west of Haerbin,south-east of Daqing,north and west of Suihua,the central of Hegang.Daxinganling area and southeast semi mountainous belonged to low-less low risking zone and where the probability of occurrence also low.Actual disaster results were matched with risking zone, especially the distribution of high low high areas.

Key words: Flood and waterlog, Geographical Information System（GIS）, Risk zoning, Fatalness of disaster-inducing factors, Sensitivity of disaster-forming environments, Vulnerability of disaster-bearing bodies