Zheng Hong-gang (1727–1787), courtesy name Jiyuan, pseudonym Meijian. He inherited his father Yu Feng's medical expertise, specializing in throat diseases and internal pediatrics, with particularly outstanding achievements in throat diseases. His works include *Zhonglou Yuyao*, *Shayu Yiyu*, *Smallpox Zhengzhuan*, *Lingyao Mifang*, and others. *Zhonglou Yuyao* is an important work in Chinese medicine on throat diseases, elucidating the fundamental theories, dialectical treatment, and internal and external prescriptions for throat diseases, with a dedicated section discussing acupuncture and moxibustion therapies for throat conditions. The book offers unique insights into the pathology of diphtheria, stating that diphtheria "resides in the shaoyin meridian, where heat pathogens lurk, stealing the mother-element/phase qi of the lung metal, thus causing white patches in the throat." It advocates the use of nourishing yin and clearing lung heat to treat diphtheria, which has had a significant influence on later generations.