This book discusses the molecular, cellular and physiological processes of salt tolerance in cyanobacteria. It is divided into three sections, each explaining different aspects of cyanobacteria. The first section covers the principle, characteristic and fundamental physiological processes, the second section descripts the cyanobacterial diversity, genomic context and genome mechanism, and the last section discusses the molecular machinery, cellular response and physiological regulations for salt tolerance. This book provides a key reference for basic and advances in the field. This book can be used as a reference for researchers, scientist and students whose work on cyanobacteria, stress biology and response.