Abstract This research aims to investigate the the effect of the dynamic of water physicochemical changes to structural community of phytoplantonic creatures in swampy flood plain. Water samples were taken in May to November 2015 in Bangkau swampy flood plain. Multivariate analysis non-metric multidimension scaling (NMDS) was used for statistically analysis the relationship of biotic and water physico-chemical data. Oscillatoria, Gonatozygon and Thallasiossira are three of twenty species, which they always present in each observations. Abundance of phytoplanktonic ranges between 148 to 23,740 cell L-1 . The presence of phytoplanktonic mainly abundance in November (16 to 20 genera) and very rare in May. Identified 20 genera, there 6 genera have a correlation to the dynamic of water quality parameters. Binuclearia and Cryptomonas have positiey correlated to parameters of depth, SO4 and PO4. Both Binuclearia and Cryptomonas were present dominantly in May and June. In the other hand, Oscillatoria (Cyanophyta), Sphaeroplea (Chlorophyta), Diatoma and Nitszchia (Chrysophyta) shows negatively correlated to the dinamic water quality. Key word: Phytoplankton, Flood plain, Swampy lake, Water quality