Abstract: The building of the former Yihe Spinnery in Shanghai is a protective historical building.To ensure its serviceability,appropriate retrofit is necessary.Structural analysis based on the inspection was performed.It is shown that bearing capacity or ductility of some members in the original structure or retrofit proposal are inadequate.Strengthening design was then performed using the method of section enhancement,externally bonded steel and CFRP sheet.Affection of the subsequent retrofit process on the strengthened structure was also analyzed.The historical building is then properly protected and the new manufacturing requirements are met through the retrofit and strengthening design.The proposed methods can serve as references for relative research or engineering practices.