BACKGROUND: The U-shaped relationship between alcohol consumption and diabetes mellitus was observed among western populations. However, few studies have systematically evaluated the association in Chinese. We aimed to investigate the associations of alcohol consumption with diabetes mellitus and impaired fasting glycemia (IFG) among middle-aged and elderly Chinese. METHODS: We examined 1,458 men and 1,831 women aged 50 to 70 from Beijing and Shanghai China in a cross-sectional survey. Fasting glucose, adipokines and markers of inflammation were measured. Macronutrients and alcohol consumption were assessed with standardized questionnaires. RESULTS: Compared with abstainers, alcohol consumption was associated with a decreased risk of having diabetes mellitus in women (OR: 0.41, 95%CI: 0.22-0.78) after controlling for socio-demographic factors, physical activity, smoking, family income, family history of cardiovascular disease or diabetes, macronutrients intake, body mass index, and markers of inflammation and adipokines. In men, both low and high alcohol consumptions were associated with increased risks of having combined diabetes and IFG (ORs 1.36 [95%CI: 1.02-1.82] and 1.50 [95%CI: 1.04-2.15], respectively]. In the multivariable stratified analyses among men, moderate drinkers who had drinking days of ≥ 5 days/week had a deceased likelihood (OR: 0.61, 95%CI: 0.37-0.98) and liquor drinkers had an increased likelihood (OR: 1.47, 95%CI: 1.09-1.98) of having combined diabetes and IFG respectively, compared with the abstainers. CONCLUSIONS: An approximately J-shaped association was observed between alcohol consumption and combined diabetes and IFG among men compared with abstainers in Chinese. Whether moderate alcohol intake could help decrease diabetic risk among Chinese people warrants further investigation.