Many historic buildings are of masonry construction. Existing masonry walls may be required an opening when the building usage is changed. A police station, for example, was turned into a museum. To provide constant temperature and humidity for treasures, the brick walls were required openings for air conditioning pipelines. In order to protect the corners of the opening wall from cracking due to stress concentration, a retrofitted scheme using two steel frames with L-shaped sections was proposed. The two steel frames were installed along the edges of the openings. High-strength bolts were anchored through the steel plates and brick walls. The study conducted cyclic loading tests in the laboratory of National Center for Research on Earthquake Engineering to verify the retrofit effects. Two specimens were fabricated in the experiment, namely brick-filled RC frame with openings, and brick-filled RC frame with openings retrofitted by steel frames. Experimental studies indicate that the proposed retrofitting scheme can perform very good seismic behavior, even better than that of brick walls without openings.