Surface treatment is one of the most effective techniques to improve the water wettability and oxidation resistance of graphite used in castable refractories. In this work, the above characterizations of treated graphite with colloidal silica via chemical dispersing method were investigated. The results showed the water wettability of the flake graphite were greatly improved when the minimum concentration of colloidal silica was more than 0.0025 g(SiO2)/Cm3(water). The effects of adding surface treated graphite on rheology and mechanical properties of typical alumina-silicon carbide-graphite castable refractory were investigated. Results showed that this type of graphite could decrease demanded water for casting about 3% and increase the cold crushing strength. Thermal analysis results revealed that the chemical dispersing method is disabling to increase the oxidation resistance of graphite.