Milled Phragmites australis was liquefied in organic solvents with and without catalyst in a cylindrical reactor at temperatures of 533, 553, and 573 K under supercritical conditions. The liquefied compounds were extracted with diethyl ether and benzene using an extraction procedure. The product yields without catalyst in supercritical methanol, ethanol, and acetone were found to be 55.4%, 64.4%, and 73.5% at 573 K respectively. The highest conversion to liquid products was obtained in supercritical acetone with 10% sodium hydroxide as catalyst at the same temperature in the catalytic runs. Main chemical compounds present in the liquid products obtained in ethanol without catalyst and acetone with sodium hydroxide catalyst at 573 K were analyzed and characterized by gas chromatography-mass spectrometry (GC-MS).