Abstract: The community structure of planktonic microalgae in shrimp ponds is closely related to the health of shrimp. Some beneficial planktonic microalgae can not only regulate DO and water pH but also assimilate the harmful substances such as NH4-N and NO2-N, effectively improving the culture environment. However, some can also produce toxins that harm the shrimps health. The dominant species of planktonic microalgae which have high proportion in quantity and biomass play an important role in maintaining the stability of community structure of planktonic microalgae in shrimp ponds and in affecting the functions of planktonic microalgae communities. Moreover, the distribution and diversity of microalge dominant species have some differences among different regions, culture seasons, modes and stages in shrimp ponds. The changing rule ofdominant planktonic microalgae species is closely related to the changes of various environmental factors in shrimp ponds which may affect the community structure of planktonic microalgae. The paper reviews the characteristics of community structure and ecological management of planktonic microalgae in shrimp ponds, and discusses how to provide a good microalgae-phase for shrimp culture.