Software testing appears with the invention of software. Software testing was done by programmers at the very beginning, which was also called "software debugging". With the rapid development of software development technologies, object oriented software developing methods have taken the leading place. However, object oriented developing methods not only bring convenience to software developing, but also bring software testing more challenges.This paper first tells the history of software testing. Then it analyzes the current theory of software testing at home and abroad. It also discusses traditional software testing methods, technology, process, popular testing tools nowadays and the application in the field of object oriented software testing.Based on the above, we show that object oriented software testing can not simply reuse the methods and technologies of traditional software testing because of its inheritance, encapsulation and polymorphism. Then it summarizes the testing model, methods and process of object oriented software and discusses the development model of object oriented software. According to this, software testing can be divided into object oriented analysis testing, object oriented design testing and object oriented programming testing. Orthogonal experimental design, prepositive condition testing methods, methods based on classes and mutual testing are the testing methods discussed in this paper. The process can be separated into functional testing, class testing, intra-class testing and system testing.According to the methods discussed in the first three chapters, testing methods and test cases are designed for Forum Registration System after detailed review of the specification. After analyzing the restricted conditions of each column in this system, test cases are designed by the methods of equivalence partitioning, boundary value analysis and orthogonal experimental design. By running these test cases, the function of this system has been checked as compared to the software demand.