Abstract: Several types of graphite oxide (GO) with different oxidation degree were prepared by changing the ratio of H2SO4/KMnO4, and were used as solid lubricant to modify epoxy resin coatings. Through tests of electrical and tribological properties and analysis of FT-IR and SEM, the relationships among H2SO4 content, electrical resistance and oxidation degree of GO and effects of oxidation degree on structures of GO and tribological properties of GO filled epoxy resin coatings were investigated. The results showed that the electrical resistance and oxidation degree of GO increased with increasing amount of H2SO4, and graphite layers were exfoliated to form different structures of GO. More than 95% oxidation degree GO lost its solid lubricating property and its filled coating had a poor tribological properties. The coating filled with GO of oxidation degree around 85% had an excellent tribological properties.