Statistical tests for surgical clinical research ZHANG Bo-heng.Liver Cancer Institute，Zhongshan Hospital, Fudan University,Shanghai200032，China Abstract A set of questions should be clarified when selecting statistical tests in clinical research, such as aim of study, study design, type of data, distribution of data, and sample size. Misuse of statistical tests will lead to poor quality of research, and even to opposite results. Common statistical tests and experimental designs for surgical clinical research were briefly introduced in this paper. It is followed by demonstrations of research design, features of dependant and independent variables are important to consider when choosing a statistical test. The aim of this paper focuses on how to select the appropriate statistical test for a particular clinical question.