Objective To investigate the widespread of the liver cancer risk factors in Wuwei city,where low-incidence for liver cancer and offer the cause clue to first-level prevention. Methods Investigate the risk factor and family history of the Wuwei city resident who wlth liver cancer by using case-control study.Estimate the liver cancer heredity mode with the method of Penrose and simple segregation analysis,calculate the degree of heritability with the metllod of Falconer,s regression.Detect the content of the resulting and promoting cancer fungi,volatility N-second nitroso compound in the meal,nitrate and nitrite in the drinking water and the vitamin C in the health adults'serum by means of culturing appraisement,experiment examination etc.Results The risk factom of liver cancer in the Wuwei city were history of viral 'hepatitis type B,kinsfolk tumor,the eating salting or mildewed foods,cirrhosis,drinking surface water,well water,or wine.By using segregation analysis and estimation of heredity mode show that the morbidity of liver cancer discrepancy to the monogenic inheritance mode,maybe the polygenic inheritance mode in Wuwei city.The h~2 of index case first degree relative was 58.74%.Picking out 8 kinds of nitrosamine,14 kinds of resulting and promoting cancer fungi from resident meal.The content of nitrate and nitrite was (38.97±3.14) mg/L,(0.086±0.043) mg/L respectively in shallow well water,the vitamin C in the health adults'serum in summer was(5.74±2.79)mg/L.Conclusion It can be seen that the history of viral hepatitis type B,kinsfolk tumor,eating salting or mildewed foods,cirrhosis,addicted to drink;higher content of nitrate and nitrite in the drinking water and strong carcinogens such as volatility N-nitroso compound in the meal,and also lackingprotection factors such as vitamin C are the risk factors of the Wuwei city resident who with liver cancer,Theinherit susceptivity is the internal environment of resulting cancer change.