Abstract: A new type of bileaflet mechanical valve were developed in China and finished its animal experiences study in 1995 at General Hospital of PLA. The valves were implanted in sheep tricuspid position. Seven cases were performed this kind of operation under extracorporeal circulation. The target of animal experience was:three sheep were alive more than one month according to national requirement of artificial heart valve technology. After 4 months effor we had got the target and the longest alive time of No 4 sheep was more than 3 months under no anticoagulation therapy. The animal experiences in detail were reported in this paper.