By textual research on text with differences in five Song checked books including Inner Canon of Yellow Emperor· Plain Questions（《黄帝内经素问》）

Synopsis of Golden Chamber（《金匮要略方论》）

Arcane Essentials from the Imperial Library（《外台秘要》）

Essential Recipes for Emergent Use Worth A Thousand Gold（《千金要方》） and A Supplement to Recipes Worth A Thousand Gold（《千金翼方》）

text with differences in Song checked medical books is summarized and divided into three categories: text with differences whose meanings are the same or similar; text with differences that are ambiguous but the actual content varies litter; text with differences whose meanings are also different and may have effects on clinical practice. It is believed that Song checked medical books have a certain degree of uncertainty

so that it is not advisable to follow blindly. At the same time

since the Song checked copies are taken as the current versions of important classics in the field of traditional Chinese medicine

it is quite necessary to perform synchronic and diachronic textual research comprehensively on these text with differences phenomena related to core elements on principle-method-recipe-medicines

as well as to perform textual research of differentiation and analysis

so as to pursue correct interpretation and effective use.