Red pine and Japanese larch (Larix leptolepis Gordon) grown in Korea have been the main species of coniferous resources in Korea. Especially, planting area of Japanese larch has been increased continueously in the recent years due to its superior plant type and rapid growth rate and its stocks reached approximately 4.32 million cubic meters at the present time. Although many research works have been done for the utilization of the larch wood in various ways, still many problems are existed in its chemical applications due to a large proportion of soluble extractives. In this study, chemical composition of larch extractives and chemical structure of its major component were analyzed. In order to identify the basic structure of major component, gas-liquid chromatography for separation of some completely methylated alditols as their acetates on a 3% - ECNSS-M on Gas Chrom Q. column was used. Proportion of extractives of Japanese larch wood was higher than that of other conifers and major component of the soluble extractives was arabinogalactan, a schematic structural formula which was presented in Figure 2. The molar ratio of arabinose and galactose was 1:4.5. The main chain of arabinogalactan was composed of 1,3 linked ${eta}$-D-galactopyranose residues, each of which carried a side chain, attached to the C-6 positions. The exact nature of all of the side chains is not known, but the majority of these side chain was composed of 1, 6 linked ${eta}$-D-galactopyranose residues, with 2~3 such units present per average chain. Some of the galactose units in the main chain had a residue of 3 - 0 - ${eta}$-L-arabinopyranosyl-L-arabinofuranose. In addition, a few terminal residues of D-glucuronic acid also was confirmed, attached to C-6 position of the D-galactopyranose residue. It could concluded that the main structure of highly branched arabinogalactan from Japanese larch extractive was essentially the same as those of the other larch species.