Abstract: In order to analyze accurately the influence of shear deformation on the mechanical characteristic of open thin-walled members，the shear stress non-uniform coefficient was correctly calculated by considering stress shear due to shear deformation． Based on the first-order thin-walled beam theory，the precise calculation formulas of several common open section shear stress non-uniform coefficient were got according to the principle of energy，some basic laws of the influences of the cross section shape and size parameters on the shear stress non-uniform coefficient were discussed． Results showed that as the aspect ratio increased，the shear stress non-uniform coefficient of channel section decreased first，then increased; it increased with the increase of the width-thickness ratio; as the depththickness ratio increased，the shear stress non-uniform coefficient decreases first，then increased． The shear stress non-uniform coefficient of Z section increased with the increase of aspect ratio; it decreased with increasing of the width-thickness ratio; and it increased with the increase of the depth-thickness ratio． The shear stress non-uniform coefficient of a biax symmetric I-section was a constant value．