This book is concise report of research work carried out by Dr. K. Hemalatha under the guidance of Prof. H. Somashekarappa and Prof. R. Somashekar. This book deals with synthesis of polymer composites, polymer blend films doped with inorganic salts or nanoparticles using sol-gel techniques. Also this gives various methods of characterizing the composites films and blends. Main techniques used in the text book are X-ray diffraction, conductivity, FTIR, UV-Visible measurements. These studies have been published in various reputed journals and it will be useful for researchers in this fields.