Pollution biology indices on zooplankton and benthos were used to analyze the pollution state of different areas of Dalianhu water source,in order to study the pollution characteristics of Dalianhu water source.The evaluation effects of different biological indices on water pollution were considered with its water quality indices,and principal component analysis was used to analyze its pollution characteristics comprehensively.The results showed,during summer and autumn,the range of Shannon-Wiener index(H₁)and Margalef diversity index(D)of zooplankton in different areas of Dalianhu water source was 0.3-1.8 and 1.0-10.4,respectively;and the range of Shannon Wiener index(H₂)and Goodnight index of benthos(G)was 0.81-1.26 and 0.30-0.88,respectively,which all showed it were in pollution.Correlation analysis results was in comparison with the water quality indices,showing the Margalef diversity index(D)of zooplankton and Goodnight index(G)of benthos can reflect the water pollution state preferably.Combined with the results through principal component analysis,the rank order of pollution state of different areas of Dalianhu water source was water forest>inner river>ponds>external river>lake area.The results showed the lake area of Dalianhu water source had certain ability to purify and protect water,and the pollution was mainly from interior sedimentation of organic matter and pond aquaculture.The ecological restoration measures for Dalianhu water source should include reshaping the terrain,sediment dredging,communicating water network,controlling pond aquaculture,and so on.