Epidemiology is the method used to find the causes of health outcomes and diseases in populations. In epidemiology, the patient is the community and individuals are viewed collectively. By definition, epidemiology is the study (scientific, systematic, and data-driven) of the distribution (frequency, pattern) and determinants (causes, risk factors) of health-related states and events (not just diseases) in specified populations (neighborhood, school, city, state, country, global). It is also the application of this study to the control of health problem.The epidemiology class will be given for 10 weeks by Guangyu Lu. Please enjoy learning! 本学期流行病学课程为10周，授课老师卢光玉，请大家认真学习！