The Ph. D thesis of Sanjeeb Kumar Rout entitled "Phase Formation and Dielectric Studies of Some BaO-TiO2-ZrO2 Based Perovskite System" submitted to the National Institute of Technology (NIT), Rourkela, Orissa, India in the year 2006. The thesis was examined and well appreciated by Prof. E V Colla, USA and Prof T.P.Sinha, Inda. The thesis was submitted to NIT Rourkela under the joint supervision of Prof. S.Panigrahi and Prof J. Bera of the institute. The tesis presents a detailed phase formation, structural, microstural and dielectric study of some BaO-TiO2-ZrO2 Based Perovskite systems. The special attention has been paid the relaxor behavior of some compositions. The author has made an attempt to shift the transition temperature of the observed relaxors towords the room temperature.