This book is a research work on natural product chemistry,isolation and characterization of bioactive components from the flower of Cassia alata lnn. The cassia alata lnn flowers was extracted sequentially with pet. ether, ethyl acetate, acetone, ethanol and water using soxlet extractor. Phytochemical screening and antimicrobial analysis (agar diffusion method) were discussed. thin layer chromatography and column chromatography techniques were employed for the isolation and purification of the active components. FTIR analysis used to identify the functional group of the compound so isolated. This book may be important for natural product chemist because what was discussed in the book may aid to understand the possible compounds from plants used by traditional healer and the possible microbes they might inhibit.