This report presents the system and the design method of the automatic design system for cantilever sheet pile breakwater and quaywall.
　Using this system, we are able to design cantilever sheet pile breakwater and quaywall on the sandy soil ground.
　This systems has two functions as follows:
(1)　Examine a stability of structure for a given section.
(2)　Minimize the required amound of steels for the design of structures being given allowable stresses and deformations.