Crown ether is an early example of macrocyclic compound, crown ethers are generally composed of repeating ethylene components containing several ether groups. Crown ethers have the remarkable properties of recognizing and binding specific metal cations in complex mixtures. Schiff bases have played a significant role in the development of co-ordination chemistry as they readily form stable complexes with most transition metals. Therefore, this book highlighting on synthesis of crown ether Schiff bases, different types of crown ethers and its applications in various areas like, ion selective electrodes, catalyst, as a liquid crystals and metal complexation etc.