Synopsis Erstwhile Bihar, lying close to the foot hills of Nepal and covering an area of 1,73,877 sq km, harbours a very rich and diverse flora. Its unique phytogeographical position, topography and good precipitation are some of the important factors which are mainly responsible for high degree of plant diversity. The occurrence of different types of forests, ranging from subtropical to tropical and consequently the establishment of three National Parks and twenty Wildlife sanctuaries in the state, which constitute an important source of germplasm, are of considerable interest. Although the state has been botanically surveyed since 1848 and the Flora was published during 1921-1925 which included Bihar, Orissa and parts of West Bengal, but the complete Flora of Bihar itself is not in hand. Simultaneously, the natural vegetation since Haines’ publication has been continuously and increasingly under pressure owing to developmental projects including mining activities and non-judicious exploitation of plant resources. These reasons coupled with the publication of a number of new plant records for the state warrant the need of fresh estimation of current status of floristic account n the state. The present work is an attempt in this direction to provide the status of the Flora of the state. It is hoped that this publication will be highly helpful to the botanists, especially taxonomists, environmentalists, foresters, agriculturists, horticulturists, pharmacologists and planners in their research and management programmes. Further, this will also fulfill our commitment to the Convention on Biological Diversity (CBD).