Atmospheric chemistry is an emerging interdisciplinary field that develops at the intersection of atmospheric science, physics, chemistry, and other disciplines. Since the Industrial Revolution, atmospheric pollution issues have continuously arisen, and atmospheric chemistry has evolved through the process of discovering and solving these problems. It is a problem-oriented research discipline that studies atmospheric composition, physical and chemical processes in the atmosphere, and their environmental and climate impacts. Atmospheric chemistry involves the characteristics and changes of various components in the atmosphere, including their sources, forms of existence, chemical transformations during migration, and eventual disappearance, covering their entire lifecycle. Research subjects include trace and minor gases in the troposphere and stratosphere, aerosol chemistry, and cloud and precipitation chemistry. The main research methods in atmospheric chemistry include field observations, laboratory simulations, and model calculations. This course will introduce undergraduate students to a preliminary theoretical and application system of atmospheric chemistry from three aspects: basic principles of atmospheric chemistry research, research methods, and major research applications. It will help students consider the impact of human activities on climate change from multiple perspectives and understand the significant role of atmospheric physical and chemical processes in these changes. After completing this course, students will grasp the basic physical and chemical processes affecting atmospheric composition and quantitatively understand the potential impacts of atmospheric chemical processes on air pollution and climate change through simple model calculations.