By sorting out the medicines,prescriptions and their modification in Treatise on Spleen and Stomach(Piwei Lun)and Differentiation on Endogenous and Exogenous Diseases(Neiwai Shang Bianhuo),this paper investigates Li Dongyuan’s medicine-syndrome(symptom). According to the original text,the medicines are classified based on syndrome(symptom),listed one by one and then summed up and analyzed. The medicine-symptom(syndrome)mainly involve the head(including mental spirit),chest,lung,stomach,lateral thorax,abdomen,urine and stool,arthralgia,flaccidity disease,sweating and other symptoms(syndromes). The most distinctive features of symptomatic treatment with prescriptions and their modification in his two books are the combination of climate in four seasons,the transformation of deficiency,excess,cold and heat and the progressive medication.