The present publication has three important parts of Dairy Chemistry. Part 1 Physical Chemistry of Milk deals with Theory Constituents and gross composition of milk of different species and breeds of milch animals , Colloidal and Emulsion State, Physical Properties of milk, Colligative Properties of Dilute Solution, Aqueous solution of Electrolytes, Acids and bases, Oxidation-Reduction, Nuclear Chemistry and Molecular Spectroscopy. Part -2 Chemistry of Milk deals with Theory Definition and structure of milk, factors affecting composition of milk, Milk Proteins, Milk enzymes, Milk carbohydrates, Milk Lipid and Milk Salts. Part-3 Chemistry of Dairy Products deals with Chemical composition and legal standards of milk products , Cream, Butter, Ghee, Indigenous products, Chemistry of cheese, Dried Milk Products and Ice cream and Frozen Desserts. This publication will be able to meet the requirements of educationists, students and dairy/ food technologists.'