Abstract: Through site investigation of collapsed RC frames with exterior corridor (RCEC frame) in Wenchuan earthquake, the damage characteristics, collapse directions, and accumulation conditions were summarized. A scale model of a two-story RCEC frame with similarity 1/4 was designed and tested on a shaking table. The collapse process of the typical frame was reproduced in the test. From the analysis of collapse modes and test results, the relationship of the acceleration response of each floor are studied, which is corresponding to the structural damage and variation of story drift angles. The story drift angle limits reflecting different damage stages of the frame are analyzed and the dynamic axial compressions of each column are calculated. Then the failure mechanism and collapse causes of an RCEC frame are discussed. The experimental results show that the gross axial compression ratio of exterior corridor columns rises and ductility severely reduces under the dynamic axial compression caused by toppling moment, and that the crush of core concrete in the plastic hinge area of a column end is the main cause of the collapse of an RCEC frame.