The Book is an introduction about the azoesters based mesomorphic compounds. the azo group -N=N- and -COO- ester group in the series induces the LC property. The liquid crystalline state is considered as the fourth state of matter matter that mixes the properties of both the liquid and solid states and intermediate between the two in many of its property. On heating a solid substance that passes through liquid crystalline phase, the solid undergoes transformation into a turbid system, i.e. both birefringent and fluid, the consistency varying with different compounds from that of a paste to that of a free flowing liquid. Apart from these the affection of humans towards colours and dyes makes the chemist to research around the azo dyes and compounds. As a result of this azoester based mesogens has found their role in the present day demands via middle or low ordered melting types.