“Macro model” in OPENSEES is an ideal and effective method for simulating RC beamcolumn joint. Some disadvantages, however, exist in both the modified compression field theory (MCFT) and diagonal compression strut model, with which they are commonly used to obtain the shear stressstrain relation of joint core. A new method by means of strutandtie model (STM), which reflected three mechanisms in joint well, was proposed to simulate the shear stressstrain response of joint core. The deformation compatibility and equilibrium condition of the model were deduced thereafter. It was indicated that the result of STM method was in good agreement with that of test data. And it could simulate more accurately the shear stressstrain response of joint core with a wide range of stirrup ratio.