Two types of habitat were investigated in the 5 flora of the Prološkog Blata Lake In the study of the precipitated watercourse vegetation of the Prološkog Blata Lake, 10 plant species belonging to the vegetation of Potamogetonalia were found. The most populated families in the water of the lake are Potamogetonaceae and Ranunculaceae. Myriophyllum spicatum is represented in all 5 lakes. The highest percentage of plants with wide spread (60%) and hydrophytes (90%) were found. In the study of the swamp flora of the coastal part of the 5 lakes of the Prološko Blato, 60 taxa belonging to the PhragmitoMagnocariecete class were found. Domestic families in marshy flora are Poaceae, Cyperaceae and Asteraceae. Of the floral elements, plants of wide distribution (38.3%) and of life forms of terophytes (42%) are represented by alohton species (8.3%) very aggressive is the American neophyte Xanthium strumarium L. ssp. italicum is also an invasive plant. In the marshy flora of the Prološkog Blata Lake, a critically endangered Heliotropium supinum species was identified.