Abstract： This paper compiles ZHANG Zhongjing's discussions on the etiology， pathogenesis， treatment methods， and prescriptions for insomnia in his works Shang Han Lun （Treatise on Cold Damage） and Jin Gui Yao Lve （Essentials from the Golden Cabinet）. It highlights the application of various Xiang-thinking modes，which can be summarized into four major methods：utilizing Wu-Xiang to dispel wind，rest the heart and calm the mind，employing Dao-Xiang to guide yang into yin for calming the mind，using Bi-Xiang to harmonize the heart and kidney for calming the mind，and determining specific target medicine for calming the mind based on Fa-Xiang. The application of Xiangthinking in guiding the differentiation and treatment of insomnia represents ZHANG Zhongjing's inheritance and innovation of the concept of "the unity of heaven and man"， as well as an expansion and improvement of the fourexamination and eight-principle system. It enriches and compensates for the limitations and inadequacies of traditional syndrome differentiation and treatment，broadening the efficacy options for treating insomnia with prescriptions.