As a form of real world study（RWS）

registry study has been applied more and more widely. But people mistakenly equate registry study with no-intervention observational study. In fact

registry study include both observational study and randomized controlled trials. In this paper

the concept of registry-based randomized controlled trials（rRCT） was discussed

and trials of this type worldwide were collected. The paper elaborated on its characteristics of cost-saving

extrapolated results and more complete follow-up data

and analyzed its challenges from the perspective of data quality

methodology

and ethics

in order to provide a evaluation method suitable for curative effects of traditional Chinese medicine.