Pharmacological effect of a drug is based on the structural features of drug. Often subtle change in structure of a drug leads into markedly changes in the Pharmacological effect of drug. Means for a molecule to act as a drug, it is necessary that various atoms should be placed in the perfect position. Heterocyclic compounds represent an important class of biologically active molecules. Among the heterocyclic compounds, Coumarin and coumarin-related compounds have proved to have significant therapeutic potential. Initially they were came from a wide variety of natural sources and now a day s new Coumarin derivatives are being discovered or synthesized on a regular basis. This book gives brief idea about an advanced method for the synthesis of certain biologically active Coumarin derivatives.