Contents: 1. Introduction. (i) Study area. (ii) Drainage system. (iii) Geology. (iv) Climate. 2. Forest types. 3. Botanical history. 4. Floral analysis. 5. Economically important plants. 6. Threats and suggested measures. 7. Plan of presentation. 8. Taxonomic account. (i) Artificial key to families. (ii) Angiosperms. (iii) Pteridophytes. References. Index to scientific names. The Udaipur Wildlife Sanctuary is situated 14.5km west of Bettiah town in the west Champaran district of Bihar. The name of the Sanctuary was in the honour of Sri Udai Singh, one of the successors of Bettiah estate and owners of these forests before independence. It is predominantly a forested wetland, located on exbow lake (Sareyaman) and is also one of the important sites for migratory birds in Bihar. The book “The Flora of the Udaipur Wildlife Sanctuary, West Champaran, Bihar, India” provides an updated information on 283 taxa under 225 genera and 71 families. The book is presented in eight sections dealing with introduction followed by forest types, botanical history, floral analysis, economically important plants, threats and suggested measures, plant of presentation and taxonomic account. The book has been also enriched with maps of study area and 349 digital images of plants. The book will be very useful to the policy makers and researchers of this region and also encourage many other researchers and intellectuals to undertake similar research in other parts of state.