The important role of marine bacterioplankton in the marine ecosystem is certainly definite with the thorough study of bacterioplankton biomass and production. The study of microbial food loop based on bacterioplankton has shown its effect which cannot be replaced in the processes of ecosystem dynamics. It is an important supplement to marine food chain, especially in oligotrophic pelagic marine ecosystem. In different water layers and special environment, the study of bacterioplankton has great potentialities and therefore is greatly concerned by many scientists. In this paper, there are also some information on its domestic study and further study needed in the near future.