Syndrome element differentiation has always been a hot topic in Chinese medicine. It is an important bridge to connect Chinese medicine, big data and artificial intelligence. Although there are still some problems in syndrome element differentiation, it still has a good prospect. Based on the research trends in recent years, we summarized some problems in the study of syndrome element differentiation. The time of the disease, the main line of chief complaint, the application of disease types, constitution and syndrome element, the equivalence of syndrome elements combination and etc. need to b...