In order to study the mechanical behavior of recycled aggregate concrete(RAC) under triaxial compression, 24 cylinder specimens were tested by considering the parameters of concrete strength, lateral confinement and recycled coarse aggregate(RCA) replacement ratio. The failure patterns of the specimens were observed in the tests. The stress strain curves, peak stress and peak strain were obtained. The formulas for calculating the strength, elastic modulus and peak strain were put forward. The test results show that the failure pattern of RAC is the shear failure. The elastic modulus, the peak stress and the corresponding peak strain are enlarged with the increase of lateral confinement, and after the peak point in the stress strain curve, the descending branch is gentle and the ductility is better. Finally, based on the Mohr Coulomb failure criterion the strength criterion of recycled concrete is discussed.