In our mother land most of the ponds are artificially created dugout basins. Ponds are the great resource of fresh water which is characterized by floral and faunal population. Aquatic plants contribute to maintaining key function and related biodiversity in fresh water ecosystems. The diversity of aquatic weeds reflects limnological status of an ecosystem. Phytoplankton is called the earth's primary producers. phytoplankton bears a significant importance role of food chain. Water pollution is the degradation of water quality, as measured by biological, chemical, or physical criteria that can make water unsuitable for desired uses. To evaluate the water quality, the impurities in the water are usually classified as physical, chemical, nutrient and biological characteristics. In our country only some reports are available regarding water quality parameters and algal taxonomy of the pond ecosystems. There is no extensive work was done in Bangladesh especially in Chittagong area except a few. The above considerations have led to undertake the present work on the phytodiversity and the water quality of selected aquatic ecosystem of Raozan Upazilla areas.