Amino acids are the building blocks of proteins which in turn are the basis of all biological processes. The Complete Information System of Amino Acid (CISAA) is the first to provide the complete range of updated data for all the 20 Amino Acid present in the naturally occurring proteins. It contains the complete information regarding amino acids including their classification, structure, chemical and physical properties, metabolism (anabolism and catabolism), their role in the biological system and much more. We have tried to compile this information system as much as interactive and useful from study and research point of view. Unique collection of all the Amino Acid's data and different properties at a place is its specialty. It provides the maximum possible updated information on Amino Acid. The incorporation of generally applicable Bioinformatics tools for the analysis of Amino Acid in a protein makes it really useful.