We examined the relations on the contraction, temperature and distillation products of wood in the course of carbonization under various conditions. And for the purpose of leading the results for application we carried out an experi-ment using K. B. S, apparatus, which is for the measuring of melting pt. of coal, and examined the following items by using the representative species of wood which were previously, chemically treated and untreated; 1. Comparison of the contractions towards various directions by conversion of timber. 2. Measurements of the contraction ratios of various species of wood. 3. Difference of the contraction ratios between sap and heart wood. 4. Reaction of constituents during carbonization. 5. Contractions during rapid carbonization, the retort was previously heated to carb-onization temperature and then test pieces were thrown into it. The abstracts of the results of above experiments are as follows: (1) From the stand point of the method of conversion, the contractions and the temperatures change in various directions, such as A longitudinal, B edge grain and C flat grain directions. In A and B directions, the con-traction began at about 100°C, slowly proceeded and in C direction, it began at about 270°C, rapidly proceeded. (2) With the various species of wood, the contraction in A and B of soft wood were generally larger than those of hard wood, and in C, the reverse was the case. Contraction of Moso-chiku (phyllostdchs pubescens magel) were generally smaller, especially in diameter direction. (3) With Mizunara (quercus crispula blume) the ratio of contraction in A to that in B was about same, but in C, the contraction of sap wood was larger than that of heart wood. (4) When the retort was heated previously at the temperatur of carbonization, then test pieces were thrown in, a rapid carbonization occured. In this case the contractions and the outbreak of each constituent occured in very short time and the contractions of sap wood were especially larger than those of heart wood. (5) The contractions of Mizunara test-pieces, which were previously impregnated with chemicals such as CuCI and then carbonized were smaller than those of untreated ones. (6) When Mizunara test pieces first treated with soda acetate and other chemicals ancj then carbonized by the same method, the contractions in all direction were larger and the yield of distilled tar were higher than those of untreated ones.