Abstract: The equilibrium moisture contents (EMC) of wood varies with the relative humidity and temperature of the surrounding air. On the basis of the measured data in Guangzhou during 1972-1974, the following linear regressionequation has been obtained: W_e=2.657557-0.01391679t+0. 2315497φ Comparing the measured data of the EMC of Beijing, Harbin, Shiyan Xiamenand so forth with the caculated values by the above linear regression equationand curvilinear regression equation in the textbook, it is considered that thelinear reqression equation is more suitable than the curvilinear equation toexpress the relationship between EMC and condition of air. The author have also described the moisture absorption as well as desorption of wood in detail.

Key words: Equilibrium moisture content of wood, Moisture absorption hysteresis, Linear reqression equation, Graph of t-φ-W.