Molecular Gas Dynamics originates from lectures and seminars delivered by the author at various universities and institutions worldwide. These materials are supplemented and arranged in a form appropriate to a graduate textbook on molecular gas dynamics, or gas dynamics on the basis of kinetic theory. The book provides an up-to-date description of the basic theory of molecular gas dynamics and its various applications giving interesting and important gas - namic phenomena. The progress of molecular gas dynamics in the last forty years has greatly enhanced the contents of the basic theory and provided inf- mation on various interesting and important gas dynamic problems. This has made it possible to compile a new graduate textbook on molecular gas dyn- ics. The present book re?ects these developments providing working knowledge: theory,techniques,andtypicalphenomenainarare?edgas(low-densityand- cro ?ows), for future theoretical development and applications. The book begins with a brief presentation of the fundamental properties of the Boltzmann equation and a summary of notation used globally in subsequent chapters of the book. A full explanation of the fundamental properties is given in Appendix A. The author hopes that readers of various backgrounds can proceed quickly to the main subject, with reference to Appendix A if necessary.