Among the conducting polymers, polyaniline (PANI) has attracted attention of most of the researchers, due to the combination of unique properties like simple preparation and doping procedure, good environmental stability, relatively high conductivity and low cost and also due to their wide spectrum of applications. However, PANI, like many other conductive polymers, is insoluble in common solvents and infusible because it decomposes before melting. In order to overcome these problems many methods are reported in the literature. In the present work we have adopted two methods to overcome these problems, grafting of polyaniline onto radiation crossliked chitosan and blending of polyaniline with chitin. Optical properties, thermal properties, mechanical properties, morphology, electrical properties and effect electron beam irradiation onto these properties are discussed in this monograph. Finally the application of chitin-polyaniline blend as humidity sensor is discussed. This book is targeted to researchers and post graduate students in the field of materials science and engineering, polymer science, conducting polymers and organic electronics.