Based on reconstructing the RC chimney of the former Nanshi Electric Power Plant,which is a typical RC tube structure,into a sightseeing tower for 2010 Shanghai World Expo,it is presented the structural reinforcement scheme and reform contents,and it is described in detail the design of reinforcement and reform of the stucture. It is calculated the main indexes of the structure before and after the reinforcement. It is also checked and compared the indexes of the bearing capacity at ultimate state and normal service state for the structure before and after the reinforcement,through which the reinforcement effect was analyzed.