This textbook describes various physical, radiative, dynamical and chemical processes involved in the coupling between the Stratosphere and Troposphere. This textbook is intended for graduate students in middle atmosphere stratospheric physics, dynamic and atmospheric science courses and will be useful to all research workers in meteorology, aeronomy, atmospheric physics, atmospheric chemistry and environmental sciences. Current areas of interest, such as Antarctic ozone hole, global warming effects on stratospheric cooling are also addressed. Stratosphere troposphere exchange, transport processes in the upper troposphere and lower stratosphere and the role of stratosphere on tropospheric weather systems are presented. The information provided in the textbook will have broad applicability in other branches of atmospheric science, and will be of interest to those studying such areas as climate change, extreme weather events, and potential for the prediction of tropospheric weather systems.