Rivers play an imperative role in the development of nation and sustenance of life, which are being polluted due to acquisitive nature of human. Hydrobiology of river Ramganga from Kalagarh (upstream) to Moradabad city (down stream) also known as "Brass city", have studied for three years. Spatio-temporal variations in several physico-chemical parameters, ichthyodiversity and fishing activities in the river were undertaken. The study exploring that the downstream of the river were heavily polluted due to excessive discharge of untreated industrial effluent containing heavy metals. The fish diversity includes total 26 species belonging to 9 families. Decreasing trend in the species richness was observed when moving to downstream which was related to less DO content and high load of pollution in the river. On the basis of Water Quality Index (WQI) the river was classified into permissible, slight, moderate and heavily polluted.Multivariate statistical methods were used for interpretations of hydrochemical parameters. The book would be of interest to Academicians,Aquatic Scientists, Researchers,Water works department,fishery department, Planners and Policy makers of river basin.