Abstract: Generally,rock triaxial compression tests were done under limited different confining pressures.The stress-strain curves obtained under certain confining pressure reflected certain constitutive relation of the rock,and the practicability of studies on the constitutive relation of rock was limited to fitting stress-strain curves.It was considered that the stress-strain curves under different confining pressures were different greatly in shapes,but there should have be some relationship because these curves were the responses of the same rock.A method was proposed to forecast the stress-strain curves under arbitrary confining pressures based on the stress-strain curves obtained under the limited confining pressures.An example was studied,and it was shown that the proposed method was feasible.