Phytoplankton populations were studied for a one year period in 1982-83 at stations upstream and downstream from Charleston, West Virginia. Identification and counts were made to determine dominant taxa and seasonal succession among classes of algae. Comparison with past surveys show decreased phytoplankton concentrations and increased diversity which suggests water quality improvement. A number of natural and cultural factors also may be responsible for major differences between stations in cell density, composition, and patterns of seasonal succession.