Man has surveyed remote galaxies and has stood on the surface of moon but has not so far come anywhere near to completing a taxonomic catalogue of the fewer than half a million species of higher plants that grow on our planet (Burmmit et al., 2001). Botanists were exploring the floristic regions of the world for several centuries and their efforts have succeeded only in prepå a more realistic taxonomic account of the plants of Europe. The gravity of the situation is so severe in the tropics due to variety of reasons, the foremost being habitat destruction at an alarming rate leading to loss of biodiversity, essential for the sustenance of life on earth. Thus, conservation of biodiversity has gained prime consideration all over the world since the earth summit at Rio de Janeiro in 1992. The first and foremost process in ascertaining the biodiversity is the taxonomic treatment of living organisms. This can be achieved only through the process involving extensive exploration, identification and documentation. Earlier works in this branch of science in the Indian subcontinent resulted in the preparation of national and provincial floras. Further studies on local and regional floras paid increased attention at ecological level in addition to taxonomic treatment, which proved to be more beneficial in the management practices. Floristic survey plays an important role in the economic development of developing country like India. Plant communities play a pivotal role in maintaining biodiversity and its conservation (Farooque N.A. and Saxena K.G.1996). Floristic study is a necessary prerequisite for much fundamental research in tropical community ecology like modeling patterns of species diversity or understanding species distributions (Philip O.L et al 2003). India shows maximum diversity in environmental and bio–geographical conditions which lead to the development of a wide range of vegetation types which provides us essential requirements like food, fodder, fuel, medicine, timber, resins, oils, etc. Studies are considered as the backbone of assessment of Phytodiversity, conservation, management and sustainable utilization in developing and under developing countries to assess their plant wealth. Pulicat Lake is the second largest brackish water lagoon after Chilika Lake of Orissa along the east coast of India. Sriharikota is the largest spindle shaped island sandwiched between Pulicat Lake and Bay of Bengal. The other islands are Sriharikota, Venadu, Irakkum and Pernadu. However widespread human impacts have already dramatically altered or completely destroyed many island environments. Hence it is obligatory to investigate scientifically and document floristic wealth of islands of Pulicat Lake.