One important issue in undergraduate software engineering curriculum is how to help students establish the concept of software engineering at the beginning of software engineering undergraduate program and to provide a reasonable basis of knowledge and skills for subsequent courses. The "Computing and Software Engineering (CSE)", a three-semester course, is designed as the introductory course for undergraduate software engineering program at NJU in China; it tries to help students learn the comprehensive knowledge and skills in constructing small-to-medium size software. The course includes not only technical topics, such as programming and software development technology, but also professionalism and teamwork through constructing different scales of software. The knowledge is organized with the complete software example development demonstration, which makes it easier for students to synthesize all knowledge related in software development. CSE has been executed from 2009, and it has been refined according to feedback from students, lecturers and TAs. This paper describes the design and teaching practice of CSE.