Bark of Pine (Pinus sylvestris), Spruce (Picea abies), Aspen (Populus tremula), Black alder (Alnus glutinosa) and Grey alder (Alnus incana) have been investigated, which are most common species of wood in Latvia. A dominant bark component in comparison with wood is nonhydrolysable with 72 % H2SO4 fraction. The most summary yield of extractives with organic solvents and hot water was obtained from spruce bark, and then from aspen, black alder, white alder and pine. Obtained extractives may be use as a raw material for obtaining various organic substances. The content of mineral substances in bark is considerably large than in the same wood species. Not all classical methods of wood component analysis can applied for analysis of bark.