The extractives and structural components of four softwood and three hardvvood species vvere determined by using the converitional methods of vvood chemistry. The acid-soluble and acid insoluble lignin analyses vvere carried out in vvoods and holocelluloses to calculate the true yields of holocellulose and lignin in each species. After the yields of holocelluloses have been corrected for the soluble lignin, the sum of holocellulose- and lignin percentages came up to about 99 for ali vvood samples. Moreover and as expected, the amounts of acid-soluble lignin in hardvvoods vvere higher than those in softvvoods. In comparison to softvvood holocellulose, the holocellulose of hardvvoods also contained higher amounts of acid-soluble lignin. From the results can then be concluded, that the conventiona! delignification vvith acidified N aC I02 solution is insufficient to remove lignin, especially, from hardvvoods.