Milled Heracleum persicum stalk was converted to liquid products by using organic solvents (methanol, ethanol, acetone, and 2-butanol) with catalysts (10% NaOH or Na2CO3) and without catalyst in an autoclave at temperatures of 518, 538, and 558 K. The liquid products were extracted by liquid-liquid extraction (benzene and diethyl ether). The percentage yields from supercritical methanol, ethanol, 2-butanol, and acetone conversions were 49.1, 55.7, 58.7, and 71.0 at 558 K, respectively. In the catalytic run with NaOH, the highest conversion was obtained by using ethanol as a solvent at the same temperature. The yields of conversion were analyzed by GC-MS.