It is of great significance to select the appropriate outcomes when evaluating the effect of an intervention. The core outcome set（COS） is an agreed and standardized minimum set of outcomes that should be reported in all clinical trials of the same disease

which is key to standardize the use of outcomes. This paper reviewed the background and development history of COS and revealed the importance of COS researches. Based on the actual use experience

the characteristics and limitations of two registry platforms（COMET database and Chicos webpage） were also introduced

and the rational selection and use of different databases and platforms were analyzed. Currently

the COS method is not yet comprehensive. And regarding the particularity of traditional Chinese medicine（TCM）

there are certain problems to be solved in developing COS for TCM

including the standardization of original outcomes

the overlapping of outcome categories

the implementation difficulty to widely seek the international consensus

and the inadequacy of the reflection of TCM characteristics. It is expected to provide references for various stakeholders in developing COS for clinical trials.