Abstract：The shape equation of KⅠ，KⅡ，KⅢ for rock compression and shear fracture nucleus of the earth¢s crust，when the coefficient KⅠ is less than 0，is given. The shape and character of KⅠ，KⅡ for compression and shear fracture nucleus with the shape of leaf，and KⅠ，KⅢ for compression and torsion fracture nucleus with the shape of bud are analyzed. Compression and torsion of direct shear fracture test and rupture state of marble samples are introduced. The rock rupture state can be seen in the microcosmic photo of the notched area of compression and shear fracture samples before failure. The results agree well with the theoretic analytic results. The extension length of rock compression and shear fracture nucleus of the earth's crust is discussed，and it is verified by in-situ findings of geological investigation.
