Based on the experimental investigations of loadcarrying capacities of super thinwalled highstrength coldformed steel channel columns with intermediate stiffeners in web subjected to axial compression,the calculation method for the effective area of coldformed thinwalled plate elements with intermediate stiffeners was discussed with reference to the related calculation formulas,and an equivalent element method (EEM), for estimating the effect area of coldformed thinwalled steel plate element with intermediate stiffeners consistent with estimated method for three different stiffened element was put forward.Finally,a comparison of the experimental results with the theoretical analysis shows that the proposed method is effective and suitable for Chinese coldformed thinwalled steel specification.