本文利用三維個別元素分析法程式(3DEC) ，模擬三維規則節理岩體在單軸與真三軸應力下之變形與強度特性。主要研究結果如下: (1) 3DEC 可用以定性分析三維節理岩體力學機制，利用該程式可簡易探討任何節理分佈位態下之力學行為，免除物理模模型模擬試驗之困難; (2) 多軸應力下岩體之異向性行為亦可透過3DEC 模擬分析，定性上均與物理現象相互一致; (3)在節理間距、勁度比較大的岩盤較需要比對二維與三維分析之差異。 This paper uses the 3DEC to analyze the mechanical behavior of rock masses under multiple axial stresses. Some conclusions are drawn as follow: (I) The 3DEC program can be employed to simulate the qualitative behavior of three-dimensional rock masses well. This approach simulated by 3DEC will avoid the difficulty performed in the physical model testing. (2) The anisotropy characteristics of rock mass are also reveal in the results of 3DEC modeling. (3) In the cases of stiffer mass with large spacing, the difference between the 3-dimensional and 2-dimensional analysis should be taken into account.