The present book opens its contents with the introductory ideas about the earth's crust, rocks, minerals and soils, along with the weathering sequence and stability of the silicate minerals; soil colloids, covering the structural aspects and properties; ion-exchange processes in soil, including the theories - both thermodynamic and kinetic as well as others - and practices, and also the implications of such processes in soil; chemistry of soil acidity and salt-affected soils and their amelioration; soil organic matter, including its chemistry, influence on soil properties, metal-humic interactions and clay-humus complex; chemistry of phosphorus, including the thermodynamic and kinetic aspects as well as its availability in soil as plant nutrient; chemistry of micronutrients in soil; chemistry of waterlogged soils; transport processes in soil, covering self- and tracer-diffusion of nutrients in soil, isothermal and thermal diffusion of water and solutes in soil, and also the isothermal coupled transport of aqueous solutes in soils and clays; and finally the issues relating to environmental soil chemistry, their impact and appropriate remediation measures. The emphasis throughout the book has been to relate the underlying soil processes to the concepts in basic sciences. Indeed, keeping in view the requirement of the beginners as well as the advanced students, there appears to be a genuine need of a textbook on the subject of Soil Chemistry which, while starting from the basic principles, would go to more intricate treatments to facilitate the understanding of the nature of the chemistry of a multi-phase and complex natural resource, namely soil. The author has made an attempt to bridge this gap. The book is written to address the requirement of the course curricula in soil chemistry for the post-graduate and Ph.D. students, notwithstanding the fact that it also caters the need of the undergraduate students, studying soil science as a part of their undergraduate course curricula.