Abstract： Objective:To analyze the body composition and influencing factors of lean non-alcoholic fatty liver disease in population receiving health examination.Methods:This is a cross-sectional study. Between January 2020 and December 2021, 1 342 individuals who had complete and reliable results of liver transient elastography and body composition testing, with a body mass index (BMI)<24 kg/m 2 and who met the inclusion criteria, were selected from the physical examination population at the Health Management Center of Jiangsu Provincial People′s Hospital. The results of body composition analysis, blood biochemical indexes and liver examination were collected from the subjects for analysis. Method of inter-group comparison: quantitative data that conform to normal distribution were tested using independent sample t-test, while non-conforming data were tested using rank sum test; count data were tested using chi-square test. The binary logistic regression analysis was used to analyze the influencing factors of body composition in lean non-alcoholic fatty liver disease in health examinees. Results:The detection rate of non-alcoholic fatty liver disease was 13.3% in all participants, and it was significantly higher in men than that in women (23.3% (125/537) vs 6.6% (53/805)). The fasting blood glucose (5.15, 5.08 mmol/L), hemoglobin A1c (HbA 1c)(5.5%, 5.6%), triglyceride (TG)(1.70, 1.64 mmol/L), low density lipoprotein cholesterol (LDL-C)(3.37, 3.27 mmol/L), alanine aminotransferase (ALT)(27.0, 21.9 U/L), aspartate aminotransferase (AST)(24.1, 24.0 U/L), gamma-glutamyltransferase (31.4, 21.1 U/L), uric acid (UA)(391, 296 μmol/L), body fat percentage (23.9%, 33.7%), waist-to-hip ratio(0.90, 0.89) and visceral fat area (70.3, 97.0 cm 2) in men and women with lean nonalcoholic fatty liver disease were all higher than those in the population without fatty liver, while the density lipoprotein cholesterol (1.25, 1.32 mmol/L) was lower. Logistic regression analysis showed that BMI, HbA 1c, TG, UA and waist-to-hip ratio were risk factors for lean nonalcoholic fatty liver disease in men, while BMI, HbA 1c, TG, UA and body fat percentage were risk factors for lean nonalcoholic fatty liver disease in women (all P<0.05). Conclusion:BMI, HbA 1c, TG, UA, body fat percentage and waist-to-hip ratio are associated with the development of lean nonalcoholic fatty liver disease.