Abstract: In order to understand the path of influence on estuarine copepods community structure and diversity in Xiangshan bay in summer, 24 samples were conducted near the beach of two power plants at twelve sampling stations (G1~G5 near Guohua power plant, and W1~W7 near Wusha Mountain power plant) in July~August, 2016.A total of 11 species of Copepoda (3 Cyclopoida, 4 Calanoida and 4 Harpacticoida) were found.There were two common dominant species Paracyclopina nana and Oithona brevicornis near the seawater of two power plants, as well as Acartia southwelli and Schmackeria poplesia only near the Wusha Mountain power plant.The average density of estuaries copepods community was 19.24 ind./L, wherein copepod nauplii accounted for 64.35%, Shannon-Wiener diversity index (H') was 1.16.Multiple stepwise regression and path analysis showed, thermal discharge conducted the decision factor on the development of estuarine copepods species (S) and H' in summer, and dissolved oxygen(DO) became the limiting factor in variations in S and H'.Thermal discharge had a direct positive effect on density of copepod nauplii, and primarily through DO, phytoplankton biomass(PB) could produce indirectly negative effect on nauplii again, was a limiting factor in nauplii density fluctuations.PB was a decision factor on the development of estuarine copepods community density and biomass.