Samples of kukersite oil shale and pine wood and their mixtures were liquefied with water in supercritical state in an autoclave. Chosen conditions (380 degrees C, 4 h) give synergy to desired direction in all feed compositions: yields of solid residue and gas with pyrogenetic water were lower 1.7-2.0 and 1.4-2.0 times, respectively, while the yield of the most expected component of oil - benzene solubles was - 1.5-1.9 times higher than additive yields. Rise in co-liquefaction oil yields (y) resulted completely from the rise in the yield of the polar components and depended on the share of wood in feed (x) according to equation y = -0.0089x(2) + 0.6626x + 34.846 (R-2 0.97).