Abstract: Based on the half-cylinder oxidation regime，a model was developed to simulate the fatigue behavior of the SiC coated C/C composite in wet oxygen atmosphere. Under the current experimental conditions，the fatigue failure of the C/C composite was primarily controlled by the oxidation depth，which is mostly affected by the crack width of the coating. The effects of temperature and the applied stress were discussed. Modulus reduction effect on the crack width，which caused by fatigue，is also considered. The composite mean lives under 90，105，120，135 and 150 MPa are 48660，32645，22078，12332 and 4786 cycles，respectively. Comparisons are conducted between the experimental and simulation data. The experimental and simulative results agree fairly well. Besides，the calculation is close to the practical results when the applied stress is sufficiently high and the test time is short.