The book has been divided into two parts. Fast part of in this book is the synthetic point of view and describes the oxidation of aromatic hydrocarbons (viz. naphthalene, anthracene, phenanthrene, cyclohexane, benzene, toluene, ethyl benzene and propyl benzene), aromatic phenols (viz. quinol, p-cresol, phenol and resorcinol) and aromatic aldehydes (viz. 3,4, dimethoxy benzaldehyde, 3,4,5, trimethoxy benzaldehyde) by cerium(IV) sulphate in presence of acetic acid, catalyzed by iridium(III) chloride in solution phase and in the absence of acetic acid in solid phase under microwave irradiation. Second part of my work contains study of the oxidation of toluene and ethyl benzene by cerium(IV) sulphate in aqueous sulphuric acid medium catalyzed by iridium(III) chloride from the kinetic point of view. The book described and shows that iridium(III) chloride, which is otherwise considered to be sluggish catalyst in alkaline medium, acts as a very efficient catalyst in acidic medium when used in conjunction with cerium(IV) sulphate. . It is expected that the present study will be highly useful for the synthesis of organic compounds and mechanistic aspects of o0xidation reactions.