The depletion of biodiversity is an alarming problem all over the country. The world conservation strategy suggests that the initial effort of biodiversity conservation should aim at establishment and maintenance of a network of protected area systems by making policy changes involving local people in the protected areas management and mobilising financial resources for their conservation and protection. The problem of biodiversity conservation has become a global issue. It is being realised that forests existing in a country is not a resource just for that country, but for the whole of the world. The Amazoian Rain Forests have been called the Lungs of the World as they serve to purity of the global atmosphere by release of oxygen and absorption of Pollutants. The rate of deforestation is several times higher in the developing countries than the developed countries, as the forests are being felled to generate funds and space for development. The total number of species in the world is estimated to be around 5 to 30 million but of which about 1.4 millions species have been described. The total number of plant species in India is estimated to be about 45,000 (15,000 flowering plants, 64 gymnosperms, 2843 bryopthes, 1042 pteriodophytes, 1940 lichans and 23,000 fungi). Nearly 4900 of those species are endemic to India out of which 1500 are highly threatened (MOEF, 1994). Contents Chapter 1: Plant biodiversity; Chapter 2: Phyto sociological region of india; Chapter 3: Phyto sociological region of the trans-himalaya; Chapter 4: Phyto sociological region of the west himalaya; Chapter 5: Phyto sociological region of the eastern himalaya; Chapter 6: Phyto sociological region of north-east india; Chapter 7: Phyto sociological region of the indian desert; Chapter 8: Phto sociological region of the semi-aridzone; Chapter 9: Phyto sociological region of the gangetic plains; Chapter 10: Phyto sociological region of the western ghats; Chapter 11: Phyto sociological region of the d