Ecological studies and adaptive responses of some aquatic plants in Ismailia Governorate, Egypt. The study aimed at identifying, analyzing and classifying the aquatic and canal bank vegetation along the aquatic habitats in the study area. Determination of the adaptive responses of four dominant hydrophyte species Eichhornia crassipes, Typha domingensis, Persicaria salicifolia and Phragmites australis to the habitat conditions is given. TWINSPAN, DECORANA and CANOCO classification and ordination programs. The phytogeographical categories and life-form classification were given for the recorded plant species. 151 species belonging to 121 genera and 46 families were recorded. Of these species, 40 are hydrophytes and 111 terrestrial ones while, most of these genera are monotypic. The phytogeographical affinities of the most recorded species related to the Mediterranean origin and the dominant life form class was the therophytes.