Advanced techniques of atmospheric monitoring and modeling give us essential clues which are able to quantify human impact from the energy uses on the Earth systems like changing climate and air quality. This book focused on the source – receptor relationship with respect to tropospheric ozone. This book is based on the author''s Ph.D. dissertation in the school of Earth and atmospheric sciences at Georgia Institute of Technology. Diverse atmospheric measurements and recent modeling applications including 3-D chemical transport model and its inverse model and receptor model are used as main tools. Therefore this monograph could be a good example to show how to estimate the source constributions to tropospheric air quality for the researchers.