Using the national standard of China, “Water quality——microbial community biomonitoring——PFU method”, the protozoan community structures and their colonization procedures were investigated and the characteristics of PFU protozoan communities in the Guangzhou Reach of Pearl River were analyzed. Total 203 species of protozoa, including 44 phytoflagelates, 64 zooflagelates, 17 sarcodina and 78 ciliates, have been found during the investigation. Compared with the references, the features of protozoan communiti...