Objective · To analyze the characteristics of radiotherapy clinical trials registered in Chinese Clinical Trials Registry (ChiCTR). Methods · The radiotherapy clinical trials registered in ChiCTR before December 1, 2018 were retrieved. Their characteristics were recorded and analyzed. Results · A total of 274 registered radiotherapy clinical trials were in ChiCTR, and the number increasedyear, in which 79.9% were preregistered, 51.5% were ongoing, and 27.4% had data monitoring committees. The top four researched diseases were lung cancer, nasopharyngeal cancer, liver cancer and esophageal cancer. 53.7% were conducted in Beijing, Shanghai, Guangdong and Sichuan. 86.4% were single-center. 69.7% were fundedindividuals or units. 40.5% focused on new radiotherapy schemes. The main types of research were intervention study (50.7%) and observational study (39.8%). Enterprise-funded projects tended to larger sample size and randomization, while self-funded projects tended to blinding (all P<0.05). Conclusion · Radiotherapy clinical trials in China are relatively standardized, but the regional distribution is unbalanced, the scale of research is small, and some registration information is incorrect or incomplete.