CaSO4/β-TCP composite powders were prepared by mixing CaSO4 and β-TCP. The CaSO4 /β-TCP (VS: VP) values were varied from 3:2 to 0:1. The composites were sintered at different temperatures. Tris was used to evaluate degradation behavior of the composites. The morphologies of composites before and after degradation were studied by SEM. The results show that degradation was increased with the increasing of VS: VP and decreased with the increasing of sintered temperatures.