This book contains the academic topics of the graduation and post-graduation studies of Inorganic Chemistry according to the syllabus of Departments of Chemistry under Saurashtra University. This book basically covers all the catalysts and catalytic process important to UG and PG level students. The core content of the book is the transition metal complexes which used as catalysts in various industrial important catalytic reactions. Chapter 1 is the introductory part of the catalysis Chapter 2 is about the unique and vital catalytic steps during the catalytic cycles, for instance, oxidative addition, reductive elimination, 1,2-insertion, migration, coordination of alkenes, elimination, etc. Chapter 3 explains about the heterogeneous catalysis about Zeiglet Natta catalyst, F-T catalyst and WGSR. Chapter 4 has sole details of homogenous catalysts in various industrial important reactions like hydrogenation, hydroformylation, oxidation, etc. Chapter 5 is regarding metal carbene and metal carbyne. Chapter 6 is the palladium-catalyzed cross-coupling. Chapter 7 is about the Green Chemistry, principles of Green Chemistry, atom economy and atom efficiency.