In order to improve the friction-wear properties of the C/C composites for aircraft brake pairs, the friction behavior of samples with infiltrating Si was investigated. The influence of Si smearing thickness on friction properties was studied in detail. The results show that with the increase of Si smearing thickness and ~SiC content, the friction coefficient reduces from 0.40 to 0.30 ; the linear wear of stators increases from 2.0/am to 18.9 ~tm per cycle, and that of rotors increases from 1.4 tzm to 22.6 btm per cycle; mass wear of stators increases from 20. 6 mg to 126.9 mg per cycle, and that of rotors increases from 13.7 mg to 166.2 mg per cycle. On the other hand, when a large number of inhomogeneous 13-SiC particulates are performed, friction surfaces of the samples flake off layer by layer and many nicks are observed.