Radical resection of hepatocellular carcinoma is the traditional treatment of choice. Hepatic artery embolization chemotherapy (TACE) can achieve good recent efficacy, but it is difficult to achieve radical treatment because of the many anatomical variations of hepatic artery, multiple sources of blood supply to intrahepatic tumors and the formation of collateral circulation by blocked vessels. Therefore, it is crucial to seek effective non-surgical treatments. Due to the advancement of radiation source, radiation equipment and technology, and the accurate positioning of various imaging examinations, radiation therapy has become more and more important in the treatment of hepatocellular carcinoma, and its efficacy has been improving. Radiation therapy is suitable for unresectable hepatocellular carcinoma that is still confined to the tumor, and its efficacy is usually better if a higher dose is tolerated. After the traditional radiotherapy modes such as whole liver radiation, local radiation and whole liver mobile strip radiation, external radiation therapy has now entered a new stage of precise radiotherapy. This mode of radiotherapy can make the high dose area of radiation consistent with the shape of tumor, so that the tumor area can receive a higher amount of radiation while protecting the surrounding normal tissues as much as possible. The indications for radiotherapy for hepatocellular carcinoma are as follows: (1) hepatocellular carcinoma with cirrhosis or other medical diseases that cannot tolerate surgery or refuse surgery, including early stage hepatocellular carcinoma; (2) limited middle and late stage hepatocellular carcinoma without surgical indication, as one of the main treatment methods in combination with TACE; (3) hepatocellular carcinoma in the portal region that is difficult to be resected surgically; (4) portal vein or vena cava thrombosis. (5) Local recurrence or residual after undergoing surgery or TACE; (6) Local recurrence or intrahepatic metastasis after surgery; (7) Single or more limited metastatic hepatocellular carcinoma. Contraindications include: (1) hepatocellular carcinoma with severe cirrhosis, liver function Child-Pugh grade C; (2) diffuse hepatocellular carcinoma; (3) hepatocellular carcinoma with massive ascites.