ObjectiveTo compare the clinical therapeutic efficacy of radiofrequency ablation (RFA) and external beam radiation (XRT) in the treatment of early hepatocellular carcinoma (HCC). MethodsThe early HCC patients were collected in the SEER (Surveillance, Epidemiology, and End Results) database, from 2010 to 2015, according to the established inclusion and exclusion criteria. The patients were assigned into an XRT group and a RFA group according to according treatment plans. The propensity score matching (PSM) was performed at a ratio of 1∶4 based on age, gender, race, alpha-fetoprotein (AFP), cirrhosis, and tumor diameter. The overall survival of the patients of the two groups was compared, and the risk factors affecting the long-term prognosis for the early HCC patients were analyzed. ResultsA total of 2 861 early HCC patients were collected, including 2 513 in the RAF group and 348 in the XRT group. After PSM, a total of 1 582 patients were enrolled, including 343 in the XRT group and 1 239 in the RFA group. After PSM, the proportion of tumor with larger diameter (>5 cm) in the XRT group was still higher than that in the RAF group (P<0.001), but there were no statistically significant differences in the other clinical pathological characteristics between them (P>0.05). The Kaplan-Meier survival curves of the RFA group was better than that of the XRT group (HR=1.65, P<0.001); The stratified analysis based on the tumor diameter revealed that the survival curves of the RFA group were superior to those of the XRT group in the HCC patients with tumor diameters <3 cm, 3–5 cm, and >5 cm (<3 cm: HR=1.79, P<0.001; 3–5 cm: HR=1.50, P<0.001; >5 cm: HR=1.67, P=0.003). The results of the multivariate Cox regression model analysis showed that the older age (≥65 years), higher AFP level (≥400 μg/L), larger tumor diameter (≥3 cm), and later AJCC stage (stage Ⅱ) were the risk factors for overall survival in the early HCC patients (RR>1, P<0.05), while XRT treatment was a risk factor for shortening overall survival in the HCC patients (HR(95%CI)=1.62(1.41, 1.86)=1.61, P<0.001). ConclusionThe data analysis results from the SEER database suggest that the long-term overall survival of RFA treatment is superior to XRT treatment for patients with AJCC stage Ⅰ or Ⅱ.