Flavonoids consist of a large group of polyphenolic compounds having a benzo- -pyrone skeleton and are common constituent present in plants. Literature survey shows that secondary metabolites of phenolic nature including flavonoids are responsible for the variety of pharmacological activities like anti-oxidant, anti-microbial, anticancer, anti-diabetic, anti-HIV. Till date nearly about 131 flavonoids constituents including flavones, flavonols, flavanones, flavan-4-ols, isoflavones, isoflavans, petrocarpans have been isolated from 60 species of Astragalus genus. This led us to compile upto date isolated flavonoids isolated from Astragalus genus along with their recorded biological activities. This book will be very much helpful for the researcher working in the field of natural products chemistry. As this book quantifies the research on flavonoids of the genus Astragalus, it will also directs the future research on this important genus. Special thanks are due to LAMBERT ACADEMIC PUBLISHING for earnest interest in publishing the work.Constructive suggestions from academicians are always welcome for improving the quality of this book.