Abstract:The equilibrium moisture contents (EMC) of 19 species in both outdoor and indoor conditions were determinded in Bantou Protective Forest Farm of xiamen during 1985—1986. The results show that the mean value of EMC in outdoor condition is 15.1% and 12.4% in indoor condition. The maximum EMC is found in June, while the minimum in October.Among the 19 species, the greatest value of EMC in outdoor condition is Gryptomeria fortunei (17.1%) and the lowest is Alniphyllum fortunei (12.0%), while in indoor condition they are respectively Eucalyptus robusta (14.3%) and Paulownia fortunei (10.7%).Values of EMC for every month in outdoor condition are obviously higher than in indoor condition, with the exception of Alniphyllum fortunei.The EMC of wood varies with the relative humidity and temperature of the surrounding air, it is further found that there exists an extremely significant relationship which can be expressed in both linear and curvilinear regression equations. However, the correlative coefficient (R) and variance ratio (F) of the linear equation are slightly higher than those of the curvilinear equation. The former is likely more precise and simple in calculation than the later. It is considered that the linear equation seems to be more suitable than the curvilinear equation to express such a relationship.Finally, two graphes of t-φ-we for xiamen region are drawn up on the bases of both linear and curvilinear regression equations.