The durability of Lizhushan Port in Shengsi County, Zhejiang Province was studied. High performance concrete (HC) was partly applied in the port with protective paint was coated on it. The chloride diffusion coefficient of both HC and original concrete (OC) was tested and compared. The cost of the application of HC and the protective paint was calculated. The results show that the application of HC could reduce the cost slightly, and the chloride diffusion coefficient of HC was smaller than that of OC. The coating of protective paint could increase the cost significantly. A suggestion was made that the protective paint may be coated on key parts of the port.