In this study, effective shear stress of reinforced concrete(RC) column is presented for preliminary evaluation of seismic performance of the existing RC moment frame. First, the default values of material strength according to construction year is proposed, which can be used for preliminary evaluation before field investigation. The shear strength of a RC column is evaluated by using Japanese code, ACI 318, and FEMA 356. Failure mode of the RC column and corresponding shear stress are obtained by comparing the shear and flexural strengths. The shear strength of RC column can be simply calculated by using the proposed table, which provides shear strength with regard to construction year, clear height, and depth of the RC column.