The present review is based on papers published between 1972 and 2020 and gives Comparative information about the most common enzymes as Diagnostic reagents and their clinical applications in disorders. Activities of following enzymes: Acid Phosphatase, Alanine Aminotransferase, Alkaline Phosphatase, Cholinesterase, Creatinine Kinase, Gamma Glutamyl Transferase, Lactate Dehydrogenase, Renin, Urokinase.

Keywords : Enzymes, Renin, Therapeutic applications of enzymes, Diagnostic Reagents, Phosphatase.