Hydraulic structures and water transportation structures are both water-related structures belonging to civil engineering works. However, due to the difference of service clients, design and supervision departments, and the lack of effective communications in the long term, there exists great difference on the main design principals and methods. Thus, the construction period and cost can be different greatly. Take the inland gravitational retaining wall as an example, we bring forward the difference of the design methods and design characteristics between hydraulic structures and water transportation structures, hoping that future structural design can take the advantages of all the engineering works and come up with a unified design method, which will guarantee the safety,durability and economy.