Abstract: The absorbability and the linear expansion of 4 native broad-leaved timbers treated with 10 different solutions have been investigated.The size of specimens is 3×3×1cm.The specimens were oven-dried and placed in the solutions for 2 and 4 hours,and 1,2,4,7,12,20,30 and 40 days,and were then weighed.The results obtained are as follows: 1. The absorbability and the linear expansion of timbers are different in the different solutions within a species or in the different species within a solution. 2. The absorb rate and the linear expansion of timbers increase quickly in the first day of treatment and decrease with various degrees subsequently. 3. The linear expanisons of timbers on tangential direction are larger 1.1—3.1 times than that on radial direction. 4. Generally,the linear expansion of timbers in liquid of lower molecular weight ceased its function earlier than that of higher molecular weight ceased its function earlier than that of higher molecular weight. 5. The larger the dielectric constant the longer the linear expansion of timbers will be.