Objective] To explore core thought of Li Dongyuan’s spleen and gastric theory, grasp the basic spirit of Dongyuan theory, and better guide the clinic. [Method]Basing on some relevant theories from NeiJing, the eminent physician in Jin and Yuan Dynasties established the academic thought centering on regulating the spleen and stomach in treatment of the deficiencies. [Result]The thought revealed the cooperative function between invigorating Yang and tonifying middle-energizer and Qi. It also proposed the concept of “ Yin-fire” and the method of relieving high fever with drugs of sweet flavor and warm nature, creating a series of prescriptions of invigorating Yang and tonifying middle-energizer, which broadening the clinical treatment of traditional Chinese medicine. [Conclusion]The academic thought centered on adjusting spleen and stomach by raising Yang and tonifying Qi, broadens the TCM clinical therapy, today still effectively guides clinical practice.