The research of phytoplankton abundance dynamics conducted in June-July 2019 at Lake Tepian Batu. A study aims to know the dynamics of phytoplankton abundance. There were 3 Stations namely stasion 1 (inlet area), Station 2 (in the middle of the lake) and station 3 (in the end of the lake). In each stations, there were 2 sampling psoint, in the surface and 2 Secchi depth. Sampling was done 4 tim…