Abstract
Birganj is a sub-metropolitan town and headquarters of Parsa district (Nepal) situated at about 6 km distance towards north of Raxaul, the Indian border. There is an important water body situated in heart of the town, known as Ghariyarwa pond. An ecological study of this famous pond was made with respect to its physico-chemical characteristics and growth of planktonic algae. Physico-chemical analysis of the pond water exhibited good amount of alkalinity, chloride and phosphate which favour growth of phytoplankton. Chlorophyceae and Cyanophyceae were observed maximum during rainy season, while Bacillariophyceae during winter.