Several pollution assessment indexes were applied in the pollution evaluation of Luanhe-Beidaihe Estuary. The results of evaluation by single diversity index of phytoplankton (DIP), diversity index of zooplankton (DIZ), and diversity index of macrobenthos (DIM) showed that the environment of seven sections were all not severe polluted. Otherwise, the results of evaluation by eutrophication index (E. I.) showed that six sections (section A, B, C, D, E, and F) were in the level of eutrophication, only section G was in the level of mesotrophy. Pollution assessment by E. I. was more appropriate than biodiversity index, according to the fact of ‘red tide’occurrence in August 2009. It was suggested that the comprehensive pollution index, considering both of the response of pullution and the cause of pollution simultaneously, should be developed to reduce the the discrepancy resulted from the pollution assessment by singular index.