In the book the author discussed in brief the angiosperm flora of the fresh-water environment from the lower Ganga Delta regions of West Bengal. These individual flora should be familiar in terms of their correct nomenclature, identity, key notes, ecological setup, phenology, physiognomy and economic importance as well. It is also pointed out how far these plants are weedy and how these can be controlled and/ or utilized. There is a common belief that in the Universe each and every individual is correlated; without one the other cannot be successfully complete their life-cycle. So, for our own benefit and to avoid the pollution or to keep the nature in balance like others, these aquatic ecosystem should be conserved and scientific means and methods should be applied. Taking this view in mind, the flowering plants of the freshwater ecosystems (327 numbers) are discussed in relation to its taxonomy, Ecology and Economic Importance or potentialities. All these plant species were collected from the field by the author himself and studies the above subject at the field, the herbarium and laboratories. The experimental trials have also been made in the laboratories and in the agriculture and aquaculture ponds as well.'