The main stimulating factor in the synthesis and study of nitrogen heterocycles is the search for compounds of therapeutic importance. Quinolines and their derivatives are important constituents of pharmacologically active synthetic compounds as these systems have been associated with a wide spectrum of biological activities. Tetrazole system rarely occurs in nature, it has been an increasingly important pharmacophore in medicinal chemistry because of its metabolic stability and unique structural and electronic features. Organic synthesis that leads to organophosphorous compounds which are characterized due to their wide applications in the various fields. This book consists the study of combination in highly bioactive quinoline and tetrazolo [1,5-a] quinoline compounds with phosphonates for antimicrobial activities so as to find new antibacterial and antifungal bioactive compounds and enrich the crinoline and phosphorous chemistry. The author has given a great emphasis on click chemistry which is a modular approach that uses only the most practical and reliable chemical transformations. sakriti opis