This work summarized the experiences, rules and data about the motorcycle muffler design and manufacture. It is deemed that the results would be useful for both the designer and manufacturer to improve and refine their vehicles. The contents of this work included (1) the problems of matches between engines and mufflers, (2) the temperature effect came from catalyst and its measures, (3) the importance of assemble tolerance and machining precision, and (4) fatigue failure caused by vibration.