The Principles and Applications of a Single-chip Microcomputer (SCM) is a course requiring much practice, but the traditional experimental teaching method is not effective in cultivating students' practical ability. To deal with this problem, experiment reform was analysed, and a portable experimental device was designed which included an Internet Service Provider (ISP) download line. The problems existing in the SCM experimental teaching are introduced first. Second, the whole structure of the system, including the hardware circuit, software and experimental projects are presented in detail. Finally, the application of the portable experimental device is presented. Practice has shown that the device is easy to use, easy to carry and can greatly increase the student's interest in SCM learning. ©2013 WIETE.