The phytoplankton community in the Lake Baiyangdian was characterized based on, five surveys were carried out from April to October in 2006. A total of 155 taxa were identified by microscope. The phytoplankton had an abundance ranging from 55.5×10⁴ cells/L to 1704.8×10⁴ cells/L. The phytoplankton community was dominated by Cyanophyta, Cryptophyta and Chlorophyta. Canonical correspondence analysis (CCA) was applied to explore the relationship between phytoplankton species and environmental parameters by CANOCO 4.5. The species-environment biplots were drawn based by the result of CCA. The result showed that pH and total phosphorus were the most important factors influencing the distribution of phytoplankton species. Besides these, biochemical oxygen demand and dissolved oxygen were also important to the phytoplankton species. CCA ordination shows a slight, but significant method to understand the relationship between spatial distribution of phytoplankton community and environmental factors in lake systems.