Creep deformation in SiC/SiC composites was analysed using a new computer simulation method with time dependent interface elements. The simulation method was used to describe the crack growth in SiC/SiC composite under four-point bending of single-edge-notched beam bend-bars. Two methods were used to simulate the crack growth due to fibre creep. In one method, the creep property was introduced into the interface elements by the general method of FEM analysis. In the second method, a new technique making the best use of the potential function was used. The stage-II steady state creep deformation was simulated by both methods, and the stage-III crack growth and the transition from stage-II to stage-III could be simulated by only the new method. Additionally, the stage-I was simulated by the new method. The new method has the potential to completely simulate creep deformation in SiC/SiC composite due to fibre creep.