Xiaokebing (diabetes mellitus) is closely related to diet and there have been a lot of description about food taboos of Xiaokebing since ancient times. The thoughts originated in the Huangdi Neijing (Yellow Emperor’s Inner Canon of Medicine) and the specific discussion about them first occurred in the Shanghɑn Zabinglun (Treatise on Febrile and Miscellaneous Diseases). This theory had been accumulated and perfected in many medical books in the Wei, Jin, Southern and Northern dynasties . By the Tang dynasty, the theory had been more mature and formed its own system in the Waitai Miyao (Medical Secrets of an Official) and Yixinfang(Ishinpo). This paper systematically summarizes the description of food taboos of Xiaokebing in the classical medical books before the Tang dynasty and analyses its inherent laws to help expand and deepen academic research on diabetic diet.