Abstract： Objective To evaluate early clinical outcomes and short-term follow-up results of CL-V bileaflet prosthesis. Methods From April 2004 to May 2010， 38 patients with valvular heart diseases underwent mechanical heart valve replacement. Eighteen patients received CL-V bileaflet valve replacement （CL group） including 8 males and 10 females with their mean age of （47.4±6.2）years and mean body weight of （64.7±11.9） kg. Preoperatively，15 patients were in New York Heart Association （NYHA） classⅢ， and 2 patients were in NYHA classⅣ. Mitral valve replacement （MVR） was performed in 16 patients， mitral and aortic valve replacement（DVR） in 2 patients. A total of 20 CL-V bileaflet prostheses were implanted. Twenty patients received St. Jude bileaflet valve replacement （SJM group）including 9 males and 11 females with their mean age of （49.7±7.6） years and mean body weight of （66.1±11.1） kg. Preoperatively， 15 patients were in NYHA classⅢ， and 3 patients were in NYHA classⅣ. MVR was performed in 17 patients，aortic valve replacement （AVR） in 1 patient， and DVR in 2 patients. A total of 22 St. Jude bileaflet prostheses were implanted. Clinical outcomes， hear function， hemodynamics and blood compatibility were measured on the 7th postoperative day and 6 months during follow-up and compared between the two groups. Results There was no early mortality （＜30 d） or postoperative complication in either group. Follow-up rate was 100% and the mean follow-up duration was 19.8 （6-61）months. At 6 months after surgery， those patients who were preoperatively in NYHA classⅢ orⅣall improved to classⅠ orⅡ. In CL group， cardiothoracic ratio was 0.51±0.05， left atrium diameter （44.5±7.8） mm， left ventricular end diastolic diameter （LVEDD，46.6±4.1） mm， LVEF 65.3%±7.7%，and LVFS 35.0%±7.1%. In SJM group， cardiothoracic ratio was 0.51±0.06， left atrium diameter （45.8±9.6） mm， LVEDD （46.2±9.8） mm， LVEF 64.1%±9.0%，and LVFS 34.9%±4.7%， which were not statistically different from those parameters of CL group respectively （P＞0.05）. At 6 months after surgery， transthoracic echocardiography was used to compare hemodynamics of bileaflet prostheses with same size 27 mm in the two groups. Prosthetic transvalvular gradient was （5.1±0.9）mm Hg in CL group and （5.8±0.8） mm Hg in SJM group， and effective orifice area was （2.3±0.3）cm2 in CL group and（2.5±0.2）cm2 in SJM group，which were not statistically significant between the two groups （P＞0.05） respectively. In both groups， the level ofhemoglobin， lactate dehydrogenase and platelet at 6 months postoperatively were all within normal range and not statistically from those respective preoperative parameters（P＞0.05）. Hemolytic reaction and hemolytic anemia were not found. During early and short-term follow-up， there was no thromboembolic complications or anticoagulation-related severe bleeding events in the two groups with same anticoagulation intensity target （target INR value 1.5 to 2.5）. Conclusion Early clinical outcomes and short-term follow-up results of CL-V bileaflet prostheses are similar to those of St. Jude bileaflet prostheses. Postoperative patients have good clinical outcomes， hemodynamics and blood compatibility. Patients’ heart function significantly improve during short-term follow-up without valve-related complication. Mid-term and Long-term follow-up are further needed to demonstrate its good performance.