Abstract: A new thermosetting pitch resin consisting of condensed aromatic nuclei cross-linked with methylene bridges was prepared by polymerization of a mixture of an aromatic rich fraction from fluid catalytic cracking oils and 1,4-benzenedimethanol at 120℃ with p-toluenesulfonic acid as catalyst. Carbon fiber/resin (CFR) and carbon fiber paper/resin (CFPR) composites were prepared by the hot-pressing method. No remarkable changes in mechanical properties were found when the composites were heated at 250℃ for 10h and 300℃ for 2h and soaked in strong acids or bases for 1 to 70h at room temperature, suggesting that the composites had good thermal stability and resistance to chemical attack. The CFR and CFPR specimens were converted into C/C composites without fissures or cleavages between the pitch resin carbon and carbon fibers by further heat treatment from 950 to 1000℃ under N2 atmosphere. The length of carbon fiber pulled out from the matrix during fracture was of the order of 10μm as seen in SEM photos, indicating that the pitch resin adhered well to the carbon fibers and the CFR and CFPR composites had good mechanical strength.