A comparative study is made on seismic design of port structures based on Chinese code, US guidelines, Japanese standards, as well as the guideline of International Navigation Association. This is the sixth of the series papers and the measures for strengthening structures to resist earthquake proposed in these codes are analyzed. It is shown that in US guidelines, the criteria for identifications of regularity and irregularity of wharf and principle of pile arrangement are presented, the details of reinforcement of connection between slab and pile are highlighted. There is a great difference for the application of brace pile in seismic design in Chinese code and US guideline.