Abstract: Port Groups (Bohai Bay port group, the Yangtze River Delta port group, and Guangdong-Hong Kong-Macao Greater Bay Area port group) in China, a developing country and the port groups (Tokyo Bay port group in Japan and Upper New York Bay port group in USA) in developed countries are investigated. The relevancy of cargo throughput of ports to regional economic indicator is evaluated by means of a grey relevance model and the synergy development of ports and regional economy is evaluated by means of the VAR model. The research shows that the relevance of ports to regional economy and the synergy benefits are different for port groups oriented to different supply train. The rule of economic development tells us that the growth rate of port throughput will go down eventually, so, to watch the situation development and adapt policy accordingly is important.