Abstract: In order to combine the graphite powders and resin better, improve the performance of carbon product, phenol-formaldehyde resin(PFR)was in-situ synthesized in the graphite powders, which was used to prepare carbon/graphite (C/G) composites. The thermal performance of different resins prepared by in-situ synthesis was analyzed. The microstructure of the composites was observed. The performance of the C/G composites prepared with different kinds and contents resins was compared. The results show that the thermal stability performance of boron PFR(B-PFR) and o-cresol epoxy PFR(OCE-PFR) were better than thermoplastic phenolic (TP) PFR (TP-PFR) and thermosetting(TS) PFR (TS-PFR) in 0-900 ℃. The graphite granules and holes in B-PFR-C/G distributed more evenly than those in TP-PFR and TS-PFR after calcination. The comprehensive performance of B-PFR-C/G was better, the density, hardness and compressive strength were 1.58 g·cm-3, 47. 5 HS and 31.8 MPa when the resin content was 35wt%.