<正>对16个不同-g羽杉种源的木材密度进行了研究，结果表明：（1）不同种源间木材基本密度、气干密度和全于密度均存在显著差异，其中5号、4号和3号种源木材的3种密度均较高，而10号种源的最小；（2）16个种源落羽杉的木材气干密度、全干密度、基本密度总变异系数分别为7.96%、8.92%、8.92%，变异幅度分别为0.3232~0.5104g/cm3、0.2933~0.4629g/cm3、0.2685~0.4004g/cm3；（3）落羽杉由基干到顶部不同树高处的木材基本密度存在显著差异。12号种源的木材基本密度随树木高度的增加而逐渐增大，13和30号种源则在2.5m处较高；（4）落羽杉不同部位木材密度径向变异模式并不一致，从髓心向北，均呈现出中间高两边低的趋势。而从髓心往南，变化趋势不一致。

The surrounding rock of highway tunnel is mainly classified with the experience method now. Under the special geological condition, it is disadvantage for design and construction management of highway tunnel. Based on the combination of the multiple factors used in classifying the surrounding rock, the fuzzy theory to build the surrounding rock classification model was introduced and the ambiguity of each factors was calculated. The surrounding rock classification according to the max ambiguity, together with the special geological condition of the highway tunnel was determined.