The book is a reprint of the textbook by N.P. Kozmina "Grain breeding," revised taking into account the current trends in the development of grain science and supplemented with information on plant biochemistry. The first part of the book contains information about the most important chemicals of living organisms - proteins, carbohydrates, lipids, nucleic acids, vitamins. The second part includes the basics of morphology, anatomy and physiology of grain and seeds, properties and signs of the quality of grain and grain mass.