Some people think that in ancient times, when people suffered from diseases in a certain part or organ, pricking, tapping and acupuncture at the affected part could alleviate or eliminate pain. This knowledge of acupoints based on pain is the primary stage of understanding acupoints. Later, people got a better understanding of the parts operated on the body surface and their therapeutic effects, and found that some acupoints have clear positions and indications, and described and named their positions, which is the second stage of acupoint development, that is, the positioning and naming stage. With the deepening of the understanding of meridians and acupoints, ancient physicians classified the indications of acupoints and compared them with those of acupoints. Through continuous summary, analysis and induction, acupoints are gradually classified into meridians, which is the mature stage of acupoint development, that is, naming, positioning and meridian tropism. Meridian theory originated from Taoist practice in ancient China.