This monograph is the outgrowth of experience gained from teaching courses in intermediary metabolism in plants for B.Sc. students. My intention has been to highlight three main biochemical aspects of plant physiology to assist students to develop the knowledge that they have acquired in general university courses in botany. It is also hoped that it will prove useful to students that need biochemistry as a subsidiary subject for any kind of biological or agricultural science. This book thus represents an attempt to overview the classification, occurrence and characterization of carbohydrate, lipid and nitrogen constituents in plants. Particular attention has also been given to biosynthesis and degradation of a wide array of these constituents in plants.