Abstract: Anodic oxidation treatment was used to modify the carbon fibers surfaces of 3D woven perform. The effect of the treatment on the ablative property of 3D perform reinforced phenol composites was studied. The results indicated that the method could improve the ablative resistance of the composites. The linear ablative rate of the composites at the test surface and the maximum temperature of the backside of the composites were decreased by 7.2% and 20℃ respectively. Moreover, the pbotographs of the composites which had been ablated were studied by SEM to analyze the effects of the treatment mechanisms on the ablative performance.