This course is aimed to present a fundamental physical chemical property of heterocyclic compounds related to the reactivity, reaction and synthesis of specific ring system heterocycles. The lectures include the introduction of each heterocyclic ring system possessing the biologically active compounds as well. The synthesis of methodology for each heterocyclic ring member system including specific biological active compounds will be given. This course will help student to gain some basic drug design concept by rationalizing the structural activity relationship between biological activity and heterocyclic medicinal agents.