Abstract: In order to improve the comprehensive productivity and reduce the waste of resource, high cell density cultivation (HCDC) has been one of current hot issues in research of fermentation engineering.It can improve microbial biomass and product production substantially, and also shorten the production cycle, as well as reduce reactor volume and equipment investment.HCDC has been used in the cultivation process of almost all the microorganisms to benefit for the development of the fermentation industry and made great contribution to the aspect of resource conservation and environmental protection as well.An overview of HCDC of microorganisms was made to analyze its limitations and possible optimization strategies.Ways of HCDC and some applied examples were introduced to forecast the prospect of HCDC technology.