Constructivism learning theories hold that the knowledge students obtained is not inculcated by teacher but by themselves through meaning construction in some social cultural background with the help of others (including teacher and partners) and learning materials. Online education's characteristics are similar to constructivism learning theories, for example, the interaction between subject and object of learning, students' autonomous learning and coordination communication among students. Therefore, online course of Packing Materials based on constructivism learning theory and CNT(computer networking technology) was designed.