Objective · To observe the changes in peripheral blood CD14^dimCD16⁺ monocyte count and serum C-reactive protein (CRP) level in elderly patients with chronic heart failure (CHF) and analyze the relationship between these changes and the cardiac function of patients. Methods · 42 elderly patients with CHF (the CHF group, consisting of 18 cases of NYHA cardiac function grade Ⅱ, 18 cases of NYHA cardiac function grade Ⅲ, and 6 cases of NYHA cardiac function grade Ⅳ) and 25 healthy elderly people (the control group) were enrolled. Peripheral blood CD14^dimCD16⁺ monocyte count, serum CRP level, left ventricular ejection fraction (LVEF), and left ventricular end-diastolic diameter (LVEDD) were measured and statistical analysis was performed. Results · CD14^dimCD16⁺ monocyte count and serum CRP level were significantly higher in the CHF group than in the control group (P<0.05). In the CHF group, the CD14^dimCD16⁺ monocyte count, serum CRP level, and LVEDD of NYHA grade Ⅳ patients were significantly higher than those of NYHA grade Ⅱ patients, while their LVEF was remarkably lower than that of NYHA grade Ⅱ patients. The differences were statistically significant (P<0.05). Correlation analysis results showed that peripheral blood CD14^dimCD16⁺ monocyte count and serum CRP level were positively correlated with LVEDD (r =0.37, r =0.45, P<0.05) and negatively correlated with LVEF (r=-0.56, r =-0.33, P<0.05) in the CHF group. Conclusion · The deterioration of elderly patients with CHF is associated with inflammation and the monocyte dysfunction may exist in the heart failure process. Peripheral blood CD14^dimCD16⁺ monocyte count and serum CRP level are expected to be novel biomarkers that can reflect the severity of heart failure.