Regarding the problems of port operations caused by long-period waves，we study the successful cases of long-period wave mitigation in foreign ports，and propose five countermeasures including restraining long-period wave sources，optimizing plane layout，constructing wave absorbing structures，improving mooring configuration and developing prediction system. The study shows that rubble mound breakwater（width not less than 30 m）and vacuum mooring system（MoorMasterTM，Auto Moor，et al.）and hydraulic mooring system（ShoreTension?）are effective and low-cost countermeasures，which may serve as reference for similar projects.