Objectives To evaluate the prevalence of alcoholic and non-alcoholic fatty liver among adult residents in Shanxi and Gansu province and to determine related risk factors.Methods By cross-sectional study in the two provinces including questionaire,height,body weight,waist circumference,biochemical tests and ultrasonographic exzamination of liver.Results A total of 1 500 persons took part in this survey.Of which 1023 were males and 477 were females.Fatty liver were detected in 247 persons.The prevalence of alcohol addict,alcoholic fatty liver and non-alcoholic fatty liver were 56.53%,3.82%,12.60%, respectively.The prevalence of fatty liver in males was significantly higher than that in females(P0.05).It was increased with the age. Multiple Logistic regression analysis demonsstrated that alcoholic fatty liver was closely related to age,hyperlipoidemia,daily alcohol intake,and BMI,of which the daily alcohol intake was the highest risk factors(OR=9.941,95%C14.803~20.577). Non-alcoholic fatty liver was correlated to age,male,hyperlipoidemia,BMI and waist circumference,of which hyperlipoidemia was the highest risk factors(OR=3.750, 95%C12.752~6.745).Conclusions Fatty liver is prevalent among adult residents in the two provinces.Non-alcoholic fatty liver is the major type.Obesity and drinking are the major risk factors of fatty liver.