Abstract: To investigate the mechanical properties of the roller compacted concrete (RCC) of a high arch dam in Minjiang river catchment, the RCC samples drilled out of the damwere tested under routine triaxial pressure and direct shearing loads. According to the test data, the properties of deformation, strength and fracture of the RCC under routine triaxial pressure and direct shearing loadwere analyzed in detail, and the constitutive equation ofRCCwas derived. The results showthatthe tangentmodulus of elasticityof the RCC under triaxial pressure is comparatively high and the compressive strength is relatively low. There is a large difference between the shear strength of RCC under routine triaxial pressure and that under direct shearing load.