Abstract: AIM: To compare the effect of combined sequences between carvedilol and quinapril on serum MCP-1 level and heart function in rats with heart failure and to identify the relation between the change of serum MCP-1 levels and the alteration of heart function. METHODS: The model of ADR-DCM/CHF was reproduced, serum levels of MCP-1 was determined by means of enzyme-linked immunosorbent assay (ELISA) and heart function was evaluated with ultrasonic cardiography. Changes in serum MCP-1 and heart function after combined drug intervention between carvedilol and quinapril for 16 weeks were compared with those in control group. Correlations between the change of serum MCP-1 and the alteration of heart function were analyzed. RESULTS: Compared with those in control group, serum MCP-1 levels of rats with heart failure were higher and serum levels of MCP-1 increased with the aggravation of the heart function. Serum MCP-1 was downregulated and heart function was improved after drug intervention with carvedilol and quinapril. Dose schedule with different sequences had no marked effect on survival rates, serum MCP-1 and heart function in rats. There were positive correlations between the amelioration of heart function and the downregulation of serum MCP-1 in rats with heart failure (rA=0.61, rB=0.64; P≤0.01). CONCLUSION: The level of serum MCP-1 is an objective index for estimating the degree of heart failure. Both carvedilol and quinapril improve heart function in rats with heart failure by decreasing the level of serum MCP-1. The sequence of using carvedilol and quinapril makes no marked difference in the downregulation of the serum MCP-1 in rats with heart failure and amelioration of heart function.