Abstract： Objective:To investigate the detection rate of fatty liver in multiple regions of China through quantitative CT.Methods:A total of 3 139 recruiters over 40 years old from a large sample, multicenter prospective urban rural epidemiological survey (Prospective Urban Rural Epidemiology, PURE) in 8 hospitals from 6 regions of China were enrolled. All subjects were examined by quantitative CT and their liver fat contents were measured. The detection rate of fatty liver and its distribution characteristics in different age and gender groups were analyzed.Results:There were 1 418 (45.17%) subjects were detected with fatty liver out of the total 3 139 subjects. The highest detection rate was found in Shanxi Province with 167 subjects (76.61%) detected with fatty liver out of 218 subjects, and the lowest detection rate was found in Liaoning Province with 144 subjects (26.62%) detected with fatty liver out of 541 subjects. There were 620 (52.06%) and 798 (40.97%) subjects detected with fatty liver in 1 191 male and 1 948 female subjects, respectively, and there was significant difference in the detection rate of fatty liver between males and females (χ2=36.716, P<0.001). There were 137 (38.38%), 374 (47.10%), 590 (45.67%) and 317 (45.55%) subjects detected with fatty liver in 357 aged 40―49 years, 794 aged 50―59 years, 1 292 aged 60―69 years and 696 aged ≥70 years subjects, respectively. There were statistically significant differences in the detection rate of fatty liver between males and females aged 50―59, 60―69 and ≥70 years (χ2=13.863, 11.497, 8.504, all P<0.05), and there was no significant difference in the detection rate of fatty liver between males and females aged 40―49 years (χ2=3.188, P=0.074). Conclusion:Quantitative CT has a certain application value in the detection of fatty liver.