The C/C composite was rapidly fabricated by Multi-factor coupling fields CVI in a home-made reactor with propylene as carbon source and carbon felt as porous preform. The effect of the temperature and pressure on microstructure and properties of the C/C composites was investigated. Microstructure and morphology of the C/C composites were characterized with optical microscopy, SEM, XRD and Raman spectroscopy. The results show the C/C composite has rough laminar pyrolytic carbon and higher density at conditions of 650°C and 12kPa in 12h. The observed regenerative cones were formed by amplified layers on defects. A new type of pyrocarbon was observed with graphitization degree 77.9% and crystallite size 30.5 nm and Optical and SEM morphologies reveal its peculiar structure. It is called “dot structure” pyrocarbon and its formation mechanism is simple proposed.