Coal electro-oxidation in sodium hydroxide solution with catalysts, K3Fe（CN）6, sodium hypochlorite and sup- ported FeS, were investigated, respectively. Gas produced from electro-analysis of coal slurry was collected by drainage-method and l-t curves were recorded to testify the catalysis of each catalyst for coal oxidation. The results show that the three kinds of catalysts can obviously improve the coal oxidation current. Furthermore, K3Fe（CN）6 and sodium hypochlorite played an indirect oxidation role in the electrolysis process. Catalysts bridge the coal par- ticles and the solid electrode surface, thus increase the coal oxidation rates. The changes of catalyst content during the electrolysis were further determined by quantitative titration to discuss the catalytic Mechanism. The dynamic transition of K3Fe（CN）6/K4Fe（CN）6 and ClO^-/Cl^- are proposed by iodometric method.
