Abstract: Nine specially shaped reinforced concrete (RC) columns with different limb lengths were tested under low reversed cyclic loadings. The influence of the flange on the shear resistance of specially shaped RC columns was studied. The truss-arch model is also used to study the stress of specially shaped columns at their ultimate shear limit state. The results show that the shear resistance is composed of two parts contributed by a truss model and an arch model, and the flange can promote the shear bearing capacity of specially shaped columns for it participates in the truss-arch action. At last, a formula based on the truss-arch model is presented to calculate the shear resistance of specially shaped RC columns by considering the flange. The calculated values are in good agreement with the experimental results.