Abstract: Because of the change of functions，a five-story frame-shear wall industrial workshop was reconstructed to a nine-story frame structure building used as top quality office building． The field inspection and seismic appraisal of the original building were conducted，the results showed that the building could meet various requirements of the present Chinese code basically． Based on the actual situation，like original large-span prestressed beam section was too high， the indoor retrofitting design program was made． Strengthening designs were proposed， including strengthening its base with two kinds of pile foundations，enlarging cross-section of original frame column and sticking CFRP laminates． Structure after adding layers was analyzed，settlement monitoring during the transformation process was carried out，and the retrofitting effect was excellent．