Objects To evaluate the immunosuppressive effect of marine preparation JLB extracted from Argopecten irradisus on aortic valve allograft durability. Methods The aortic valve homograft heterotopically allografted onto abdominal aorta from SD to Wistar rats. Then Wistar rats were divided into 2 groups. Test group was treated with JLB (0.5g?kg~ -1). The other group served as control. The rats were sacrificed in batches at 2, 4, 8and 12 weeks postoperatively. Blood samples and AVH were obtained for accessing the expression of CD25, CD71 and CD28. Results The expression of CD25, CD71 and CD28 in test group decreased more than that of control group at early stage of the transplantation. Conclusion JLB treatment can inhibit immune response at early stage after the transplantation.