Iodized oil deposition appeared after liver cancer intervention, and long-term deposition of iodized oil seen in imaging examination was mostly necrotic area after tumor embolization. Clinically, iodized oil is often used as a medium and chemotherapeutic drugs are injected into the blood-supplying part of the tumor. Research has proved that there is a strong affinity between hepatocellular carcinoma cells and iodized oil, so iodized oil can be chosen to intimately contact hepatocellular carcinoma cells, so that chemotherapeutic drugs can fully act on the cancer and block the arteries supplying the tumor. Some clinical data show that necrosis after tumor embolization is the main reason for long-term retention of iodized oil. Iodized oil generally does not enter into the natural necrosis area of tumor, but after entering into the survival area of tumor, due to the chemotherapeutic and comprehensive embolization effect of iodized oil anticancer drug mixture and gelatin sponge leading to necrosis of tumor, the iodized oil entering into the tumor can not be discharged and retained for a long time. Because embolization is difficult to lead to complete necrosis of the tumor, there will be collateral circulation after interventional embolization, and most of the iodine oil in the non-necrotic area of the tumor may be discharged. Therefore, clinically, the density and pattern of iodine oil deposition in the lesion can be seen by imaging to determine whether there is a new lesion or progression of the tumor.