New York，San Francisco，Tokyo，GBA and other cities in the four bay areas of the world gather a variety of high-quality resources of development factors，occupying the high ground of global value chain and resource allocation. The global economic and geographical landscape has been profoundly reshaped. This paper focuses on the four forms of flow，such as material flow，human resource flow，financial flow and information flow. The comparative studies have been made on the current situation and characteristics of the flows of the four bay areas in the world. According to the study，the New York Bay Area is known as the international immigrant capital and financial bay area；the San Francisco Bay Area is a world-renowned technology bay area，where innovation and entrepreneurship is highly active；the Tokyo Bay Area is a world-class industrial Bay Area，which is the general dispatch center for Japan’s outbound investment；GBA is a global trade center，a global shipping center，a global financial center and the emerging technology innovation center in Asia-Pacific area，which is a fast-growing integrated bay area.