Lignin gasification in supercritical water over charcoal supported ruthenium trivalent salts was studied using a batch reactor at 673 K. Ruthenium (III) nitrosyl nitrate on charcoal (Ru(NO)(NO3)(3)/C) was more active than ruthenium (III) chloride on charcoal (RuCl3/C) for the gasification reaction. EXAFS analysis revealed that ruthenium metal particles were formed in both RuCl3/C and Ru(NO)(NO3)(3)/C catalysts during the lignin gasification and that the size of ruthenium metal in Ru(NO)(NO3)(3)/C was smaller than that in RuCl3/C. It was concluded that well-dispersed ruthenium metal particles were active for the lignin gasification in supercritical water.