Abstract: Nonlinear finite element analysis for 3D-frames with special-section columns is presented considering the frame features such as irregular cross-section of the columns. The frame was divided into elements properly; substructure and static condensation were utilized to increase computational efficiency. A simplified calculation model was obtained in which zonal discrete section method and eccentricity transition matrix in master-slave systems were applied to separate and fabricate the special-section of the column. Based on the model, the method to analyze aseismic performance of the 3D-frame with special-section column was set up by PUSH-OVER method under the unilateral and reversed cyclic loadings. The proposed method was verified. The 3D-frame with various length-width ratios of column limb was analyzed by PUSH-OVER under loading in various horizontal directions. The influence of length-width ratio of column limb on aseismic performance of the 3D-frame was discovered.