Mitral regurgitation (MR) is one of the common complications of heart failure (HF). The prevalence and characteristics of MR are rarely investigated, especially in the Chinese population. The purpose of this study was to determine the prevalence and characteristics of non-organic MR in HF patients and subgroups defined by ejection fraction. A single-center, hospital-based, and retrospective chart review study included patients with heart failure admitted to the cardiovascular department from January 2017 to April 2020. Demographic characteristics, laboratory results, and echocardiogram results before discharge were analyzed in different groups defined by left ventricular ejection fraction (EF) using logistic regression and adjusted for confounders. Finally, 2418 validated HF patients (age 67.2 13.5 years; 68.03% men) were included. The prevalence of MR was 32.7% in HF, 16.7% in HF with preserve EF patients, 28.4% in HF with mid-range EF patients and 49.7% in HF with reduced EF (HFrEF) patients. In the HF with preserved EF group, multivariable logistic regression showed that 4 factors associated with MR including EF (odds ratio (OR) 0.954 (0.928-0.981), p = 0.001), left ventricular posterior wall thickness in diastolic phase (LVPWd) (OR 0.274 (0.081-0.932), p = 0.038), left atrium (LA) dimension (OR 2.049 (1.631-2.576), p 0.001) and age (OR 1.024 (1.007-1.041), p = 0.007). In the HF with midrange EF group, multivariable logistic regression showed that 3 factors associated with MR including LA dimension (OR 2.009 (1.427-2.829), p 0.001), triglycerides (TG) (OR 0.552 (0.359-0.849), p = 0.007) and digoxin (OR 2.836 (1.624-4.951), p 0.001). In the HFrEF group, multivariable logistic regression showed that 7 factors associated with MR including EF (OR 0.969 (0.949-0.990), p = 0.004), (OR 0.161 (0.067-0.387), p 0.001), LA dimension (OR 2.289 (1.821-2.878), p 0.001), age (OR 1.016 (1.004-1.027)), p = 0.009), TG (OR 0.746 (0.595-0.936), p = 0.011), diuretics (OR 0.559 (0.334-0.934), p = 0.026) and ICD (OR 1.898 (1.074-3.354), p = 0.027). HF patients had a high burden of MR, particularly in the HFrEF group. Worsen cardiac structure (LA dimension and LVPWd) and function (EF), age, and medical treatment strategy played essential roles in MR.