Abstract: As an environmentally friendly physical modification of wood, wood heat treatment technology can effectively improve wood color, dimensional stability and biological durability of wood, so it is widely used in the functional improvement of wood. In this study, Castanopsis hystrix wood was used as the research object, water vapor was used as the heating medium and the wood was heat treated for 1.5-4.5 h under the temperature of 150-210 ℃. The color changes of Castanopsis hystrix wood under different hear treatment conditions were studied, and the correlation between color and dimensional stability, mechanical properties and biological durability was also discussed. The results showed that the lightness index L^* decreased, the red green index a^*and the yellow blue index b^*increased slowly, and the lightness difference ΔL^*and the total color difference ΔE^* increased gradually, indicating that the color of heat treated Castanopsis hystrix wood gradually changed from primary color to dark color. The maximum reduction of dry shrinkage rate and wet expansion rate was 55.7% and 69.7%, respectively, indicating the dimensional stability was obviously improved. The flexural strength and elastic modulus were decreased by 3.1%-30.2% and 3.7%-20.7%, respectively. The termite resistance and rot resistance grade were not improved. In the temperature and time range involved in this experiment, there was a second-order parabolic relationship between the color change of heat-treated wood and the weight loss rate of termite-eaten wood, the survival rate of termite, and the weight loss rate of brown rot wood and white rot wood. However, the correlation between the color change of heat-treated Castanopsis hystrix wood and dimensional stability and bending resistance was unclear. Therefore, it is feasible to predict and evaluate the anti-biological durability of heat treated Castanopsis hystrix wood by color change.