The processing property and casting performance of the phenolic resin which can be used in RTM are studied. The rheological properties test, thermogravimetric analysis, oxyacetylene ablation test and other methods were used for characterization. The results show that the resin low viscosity platform (≤800 mPa·s) is long, and the applicable periods are more than 2 hours at 65~80℃.The char yield at 800℃ under N₂,line ablation rate and mass ablation rate of phenolic casting are 61.38%, 0.167 mm/s and 0.0654 g/s. The RTM phenolic resin is suitable for RTM technology and as matrix of ablative composites.