Objective · To investigate the association between mid-upper arm circumference (MUAC) and non-alcoholic fatty liver disease (NAFLD) or insulin resistance in middle-aged and elderly Chinese community population.  Methods · A cross-sectional study was conducted in 6 570 residents aged 40 years or older in Jiading District of Shanghai in 2014. All participants received standard questionnaire, anthropometric measurements, biochemical evaluation and ultrasonic examination. NAFLD was defined by hepatic ultrasonography, after excluding subjects with excess alcohol consumption and medical history of liver diseases. Participants were divided into 4 groups according to the quartiles of MUAC, then association between MUAC and NAFLD or insulin resistance was analyzed.   Results · With the increase of MUAC level, body mass index (BMI), waist circumference, systolic blood pressure, diastolic blood pressure, triacylglycerol, fasting insulin, HOMA-IR levels, low-density lipoprotein-cholesterol, alanine aminotransferase, γ-glutamyl transpeptidase, and aspartic transaminase levels were increased significantly (all P<0.01), as well as the prevalence of NAFLD, hypertension, dyslipidemia, and insulin resistance (all P<0.01). A fully adjusted multivariate Logistic regression analysis revealed that with the increase of MUAC level, the risk of having NAFLD and insulin resistance were increased among women. However, among men, there was no correlation between MUAC and NAFLD or insulin resistance.  Conclusion · MUAC is significantly associated with NAFLD and insulin resistance in middle-aged and elderly female Chinese community population.