The Gangetic plains in Bihar are characterized as Ecological region of the "Lower Gangetic Plains Deciduous Forests". The purpose of this guide is to correlate the different biological communities which inhabit the fresh waters of the Gangetic Plains. During field research of benthic macro-invertebrates, special attention was paid to macrophytes growing in the same habitats. The aquatic plants are providing an important substrate and food resource for many invertebrate animals. All macrophyte plants that are living underwater or floating on the water surface have been systematically documented and were photographed on the spot. Furthermore, herbarium collection of important finds was started to provide reference material for identification training and future biochemical studies. Here, the illustrated macrophytes are representing the kingdom Plantae with three divisions, Charophyta, Pteridophyta, and Spermatophyta. The freshwater macrophyte inventory of Bihar comprises five classes. The algae, with the acient class Charophyceae, the ferns with the very much differing classes Salviniopsida and Marslleapsida and the subdivision Angiospermophytina with two classes Dicotyledoneae and Monocotyledoneae, usually known as "higher" plants. Thirty four different aquatic plants have been recorded during the period January to August 2012 from the study area, but numerous more can be expected.