Silicon carbide matrix composites are composed of fibers, matrices and their interphases. The interphase,which connects the fiber and the matrix, has a significant impact on the performance of the composites. The most commonly used interphases are pyrolytic carbon and boron nitride. The preparation technology of pyrolytic carbon is relatively mature, but its long term use under high temperature oxidizing atmosphere is limited since it is prone to get oxidation when the temperature is above 400℃. The preparation technology of boron nitride has developed very rapidly in recent years and various new kinds of raw materials and preparation techniques have emerged. In terms of evaluation methods of the interphase,although it is very important to optimize the performance of the composites, the major problems are the difficulty in sample preparation and data dispersity. In this paper, the role of the interphase in silicon carbide matrix composites, common kinds of the interphases and their preparation technologies, the evaluation methods, and the future development trends of the interphases have been discussed comprehensively. There is a great space for further research on the development of new precursors, the development of new preparation techniques and the improvement of the utilization rate of raw materials. The further development of material properties and the design of multi-layer interfacial layer are the future trends. This paper has certain reference value for the development in the field.