SiC matrix composites reinforced by continuous carbon fibers were fabricated using an improved chemical vapor infiltration (Continuous Synchronous CVI, CSCVI) process, so that the weaving of continuous carbon fibers and deposition of SiC go along synchronously. Under different processing condition, C/SiC composites were fabricated and their microstructures were observed. The size of remnant pores of CSCVI-C/SiC composites is very small and less than that of ICVI-C/SiC composites. CSCVI process has a capacity for fabrication of C/SiC with low porosity and high density. Some characters of C/SiC composites, such as open porosity, thickness of SiC matrix and final density, are directly effected by the winding linear velocity of carbon tows.