Making an overview survey about the historical evolution process and the primary algorithm of depth datum in our country,the paper introduces the classification and development of the depth datum worldwide.Meanwhile,the paper gives a comparison about the calculate algorithm of jetty’s elevation between domestic and overseas code.It focuses on the calculation principle,combination factors and data analysis,and analyzes the definition and statistical approach of the design water level.This comparison research may be helpful to the application of domestic and overseas code in port projects.