This Chapter, an excerpt from The Yellow Emperor’s Classic of Internal Medicine, discusses traditional Chinese medicine acupuncture techniques. It details the effects of Qi imbalances in different channels according to the seasons, outlining specific symptoms and consequences of excess or deficiency. The text also explains the dangers of performing acupuncture contrary to the seasonal flow of Qi, and it describes the fatal consequences of puncturing the five vital organs. Finally, it emphasizes the importance of understanding seasonal Qi movements for effective and safe acupuncture practice.