It has been a long time that Er-hu performance which was contributed by Taiwan's predecessors has rich development and progress. However, the systematic teaching material and academic performance theory has not been established. Therefore, the author aims at the topic, Three Dimensions of Er-hu Performance, to describe the three dimensions of the knowledge of Er-hu performance, training, and showcase. Then I will discuss the relationships of mental, physical and physics, the levels of the base, the skill and the interpretation, and the relationships of composition, performance and appreciation of art. The author expects to represent some reflections over his long-term study of this field based on the discussion of the issue. I also hope that more experts and scholars can devote themselves to the research of this field to make Er-hu performance systematically and theoretically soon.