Objective: To analyze the mid long term results of prosthetic valves replacement. Methods: 2?141 patients underwent prosthetic valve replacement from 1978 to 2001, and 1?681 patients were followed up by completion of 78.5%, cumulate of 8?021.1 patient years and averages of 4.77 patient years each. The data were analyzed by multi factor regression and T test. Results: 92 patients died after operation. The 5 year and 10 year survival rates were (92.3?2.2)% and (90.1?2.7)%, respectively. The main complications were thromboembolism, valve mechanical malfunction, peri prosthetic leak, hemolysis and SBE. The heart function (NYHA) was significantly improved after valve replacement. Conclusion: The mid long term results of prosthetic valve replacement are rather satisfactory with low mortality and morbidity. Subvalvular structure preservation and tricuspid annuloplasty contribute can greatly improved heart function. Satisfactory myocardial protection during CPB is the key of successful operation.