Many epidemiological studies have been conducted in China during the last 50 years. A problem to be solved urgently is how to make the whole world know the development of epidemiology in China and to work with international epidemiologists better to solve the common public health problems that humans are facing. It became more important after the epidemic of SARS.The chapters in this book are chosen from the Chinese edition (4 volumes). Although this book does not represent the whole picture of epidemiological studies in China, it reflects the thoughts and methodologies used by epidemiologists in China and the contribution to solving the health problems in Chinese population. We hope this book will increase the awareness of foreign colleagues to Chinese epidemiologists and strengthen the communication and cooperation between Chinese and international epidemiologists.