The classic analysis of reliability and validity analysis can be spread to case study,which can promote the development of normative in case study.Reliability and validity of the case study include:Trustworthiness,internal validity and external validity.Trustworthiness has three dimensions:the accuracy of description,the integrity of description and the objective of description.Internal validity has four dimensions:interpretation validity,theory validity,the breadth of inductive reasoning and the depth of inductive reasoning.External validity has two dimensions:abstract and the breadth of application.