In order to study the mechanical behavior and the failure mode of existing RC frame structure, a real three-story RC frame structure including external masonry walls was tested by lateral loading. The global structure exhibited a column-sway collapse mechanism with shear-flexure hinges at the top ends of the columns at the first story. The external wall along the loading direction at the bottom story exceeded its ultimate capacity indicated by a large through-the-wall diagonal crack. A Local-Fine Model (LFM) is presented to capture the global-local nonlinear behavior of the test structure. Based on the damage law of the frame structure, the test structure is divided into linear regions with one-dimensional elements and nonlinear regions with three-dimensional elements in the LFM. All damages are assumed only occurred in the nonlinear regions. Different dimensional elements are coupled by the multi-point constraint equations. The calculated global failure progress, bearing capacity and the local concrete strain agrees closely with the test. The calculated local steel yield progress is in accordance with the test failure progress. Those results indicate the presented LFM can reflect the global behavior and local damages of the structure accurately.