Object Oriented Programming is an important subject for computer major students, this course not only delivers the expertise on how to write program in an OOP language, but also guides students to think in object oriented paradigm. Teachers always found themselves in confusion on which language should be used as the teaching tool. In this paper we present some reform measures took based on our own teaching experiences, by introducing the thinking in object oriented paradigm. We use C#, C++ and Java in parallel to deliver the course. By emphasizing the programming standard in coding, the students acquired the knowledge to distinguish the 3 languages in practice as well as the OOP itself.