The present title Biology of Echinodermata has been carefully compilated on the basis of all recent researches and investigation made on Echinoderms. It is intended for undergraduate and postgraduate students of all universities. The text material has been written in a very easy, clear, lucid and straight forward manner to make a clear and vivid understanding. All important types have been dealt with complete, authentic and up-to-date account including morphology anatomy, physiology and development of selected types. Efforts have been made to condense the matter as far as practicable. It is hoped that the Biology of Echinodermata will not only meet the requirement of Indian students but will also be useful as a guideline to the teachers and researchers.