In order to improve the study on microzooplankton ecology, the methods with which the grazing pressure of microzooplankton on phytoplankton and primary production were reviewed. The dilution method was discussed fully on its theoretical bases and problems. The results of the different estimation methods showed that microzooplankton play an important role in marine ecosystem.\;Process study is one of the hot spots of marine ecology study. The fate of the primary production is one of the foci of marine ecolog...