Professor Xu Huiyuan is one of the 4th batch of the veteran and famous Chinese medicine experts in the academic experience inheritance project in Beijing, who has rich clinical experience, especially in diseases of digestive system. Chronic gastritis is a common and frequently-occurring disease, the main pathogenesis of which is abnormal liver Qi. The location of the disease is in middle-jiao. Its common TCM syndromes are liver-stomach disharmony and liver-spleen disharmony. The treatment of middle-jiao disease should use harmonic methods. The most appropriate harmonizing prescription is Xiaochaihu decoction. This article summarizes the experience of Xu Huiyuan for treating chronic gastritis by using Weiyan decoction which is derived from Xiaochaihu Decoction. Also, two typical cases is included for reference.