Phytoplankton of test pool of experimsental base in Qingcaosha water source, Changxing Island, was respectively investigated from August 2011 to August 2012. Types, cell abundance, dominant species, and diversity index of Phytoplankton community structure were compared and water quality was also evaluated around ecological multi restoration of the experimental base. The result shows that: before ecological restoration, the Cyanobacteria were absolutely dominant groups; Merismopedia sp., Microcystis sp., and Pediastrum simplex were dominant species in the waterbody; the water quality in the test pool was eutrophicated seriously. After ecological multi restoration (Daphnia magna Submerged plants Fish), the effect was significant with higher water quality. Phytoplankton biodiversity was increased, and Cyanobacteria were controlled effectively，and also Microcystis sp. was no longer the dominant species of waterbody.