Abstract: Objective：To explore the angiographic distribution of the anomalous ostium of right coronary artery (RCA) and improve the technical tips for catheter incubation during right coronary angiography. Methods：A total of 24 861 patients who underwent coronary angiography in Zhongshan Hospital, Fudan University from May 2015 to May 2017 were reviewed, and the cases with anomalous RCA origin were identified. The aortic root at left-anterior oblique 40°-45° view during coronary angiography was set as an imaginary plane, which was divided into four quadrants. The ostia distributions of anomalous RCAs, the image features and the technical essentials were analyzed. Results：Totally 147 cases had anomalous RCA origin and all underwent coronary angiography successfully. Among them, 67 patients (45.6%, Type A) had an ectopic RCA origin from left sinus of valsalva (LSOV), 48 patients (32.7%, Type B) had an anomalous RCA origin from left side of ascending aorta, and 32 patients (21.7%,Type C) had an anomalous RCA origin from right side of ascending aorta. In angiography image, some special signs named as “sea gull sign” and “horn sign” were observed in cases with anomalous RCA origin from LSOV or aortic sinus crest. Such as transposition of the heart and widened aortic root, the anomalous RCA originated from ascending aorta near coronary sinus in angiography image were actually originated from LSOV in some cases. Conclusions：The anomalous RCA arising from LSOV is the most common variation, followed by arising from ascending aorta. The RCA arising from ascending aorta above right coronary sinus is relatively rare. Understanding of the distribution regularity and image features of ectopic RCAs is helpful for coronary angiography and intervention.