Through the analysis on the medical records in volume of “typhoid fever in internal diseases”from Ding Ganren’s Collection of Clinical Medical Practice,this paper summarizes Ding’s rich experience and thoughts of syndrome differentiation in treating typhoid exogenous diseases. Ding learned experience from other physicians and studied diligently. Based on Zhang Zhongjing’s syndrome differentiation of six meridians,treatments according to six meridians are proposed as the principle,which considered as the key to the analysis of illness condition and medication according to indications. Some representative medical cases are selected and their syndrome-treatment-recipe-medicines are analyzed,and Ding’s experiences in treating typhoid exogenous diseases are summarized.