Background:Nonalcoholic fatty liver disease(NAFLD)was recently proposed to be renamed metabolic dysfunction-associated fatty liver disease(MAFLD)with the diagnostic criteria revised.We investigated the similarities and differences in the prevalence and clinical characteristics of MAFLD and NAFLD in Chinese adults.Methods:A cross-sectional study of 9980 Chinese individuals aged 40 years or older was performed be-tween 2011 and 2012 using randomized,stratified cluster sampling in Shanghai,China.A detailed ques-tionnaire and the results of abdominal ultrasonography,a standardized 2-h 75-g oral glucose tolerance test and blood biochemical examinations were collected.Results:A total of 9927 subjects were included in this study.The prevalence of MAFLD(40.3%)was signif-icantly higher than that of NAFLD(36.9%)(P<0.05).MAFLD was highly prevalent in type 2 diabetes mel-litus(T2DM)(53.8%),impaired fasting glucose(35.7%)and impaired glucose tolerance(40.9%).High risk of advanced fibrosis based on fibrosis-4 was highly prevalent(14.7%)in lean MAFLD with T2DM.Among 9927 subjects,3481(35.1%)fulfilled the diagnostic criteria for MAFLD and NAFLD(MAFLD+NAFLD+),521(5.2%)MAFLD+NAFLD-,and 181(1.8%)MAFLD-NAFLD+.The MAFLD+NAFLD-group had more significant metabolic disorders than those in the MAFLD+NAFLD+group(all P<0.05).Among MAFLD-NAFLD+sub-jects,82.9%had metabolic disorders.Conclusions:The new definition of MAFLD may better reflect the pathogenesis related to metabolism.Future research should focus on studying the natural history,pathogenesis and treatment effectivity of the overlap and non-overlap of NAFLD and MAFLD subjects.