Abstract: In this paper fracturing behavior of granite and marble as well as the effect of the stress path on the rock fracturing strength,is studied by use of the rock pore-triaxial apparatus.The test results show that:(1)strength of pore-pressure fractured rock increases with increase of confining,pressure;(2)under the tensile-compressive stress the rock shows the tensile fracture and the tensile stress which causes fracture in the rock decreases with increase of the axial pressure;(3)the values of rock tension strength from hydrofracturing are higher than those from other methods.