Synopsis Floristically India is one of the richest country in the world by virtue of its climate and altitudinal fluctuations etc. During 20th century a lot of work has been done on the flowering plants of the country but Pteridophytes, of which, especially fern -allies have been remained yet as neglected group due to various reasons viz. their occurrence in inaccessible areas, inconspicuous size and habit, non expertise collections etc. Among the fern -allies also only fragmentary work has been done on the localized basis. To fillup this lacuna, the taxonomic studies on the family Lycopodiaceae have been undertaken on Indian basis, since last more than ten years, which ultimately resulted into Ph.D. degree from the Calcutta university, Cacutta in the year 1981. Afterwards a few additions were made by the Author, which are also included in the present volume. The present treatment provides taxonomic details of 25 taxa of Lycopodiaceae. Key to the genera and species, current nomenclature, detailed description, sample citation of the specimens examined for the authenticity, photographs of habit and illustrations of diagnostic value, distributional maps, bibliography, short compilation on classification, past history, cytology, anatomy, economic/medicinal importance etc. It is hoped that the present volume will be useful to the research workers interested in the taxonomic aspect of the family Lycopodiaceae as well as the postgraduate students, since it gives coverage to all the important aspects.