Abstract： Based on the related overview of exterior syndrome and interior syndrome， the authors elaborated the academic thoughts of "exterior syndrome in the interior" proposed by ZHU Weiju，a famous doctor during the period of the Republic of China，from the pathogenesis，treatment and prescription of typhoid fever of intestine. It is believed that exterior syndrome exists not only in the fur，muscle and fascia appearance，but also in zang- fu organs，bone marrow，etc.，but because of its location is deeper thus "exterior syndrome in the interior" . It is pointed out that method of using acridity to release including Guima Yin，can treat digestive diseases and urinary diseases whose pathogenesis conforms with "exterior syndrome in the interior".