[Objective]To discuss the clinical experience of treating primary insomnia with Professor GU Xizhen, the famous Chinese doctor in Jiangsu Province. [Methods]To study the understanding of the etiology and pathogenesis of primary insomnia by Professor GU Xizhen, summarize the experience of treating primary insomnia based on the use of the key suppressing Yang and basing on the syndrome differentiation.[Results]Professor GU Xizhen thinks that the movement of the Ying and Wei is the most important physiological mechanism for the formation of sleep, and that Yang does not enter the Yin is the basis of the pathologic theory, the deficiency of Qi and blood and the dysfunction of the viscera are the pathogenic factors. Based on the urgent cure of the symptoms, delayed treatment of the fundamental principles, put forward the treatment when suppressing Yang into Yin first, on the basis of the emphasis on tonifying Qi and blood, Yin and Yang, clearing heat, removing the wet, regulating Qi activity etc, matching specific time of the drug. It can relieve both primary and secondary symptoms and get good results.[Conclusion]The treatment of primary insomnia by the Professor GU Xizhen is very effective. It deserves further study and promotion in clinical practice. One medical case is attached to prove the above conclusion.