Objective　To study the effect and safety of radiofrequency ablation (RFA) in the treatment of liver cancer.Methods　The clinical data of prospectively and non-randomly selected 102 liver cancer patients were analysed. Results　102 patients with a total of 216 tumors were found in this series, the size of hepatomas were 1.5 to 14*!cm in diameter (average 4.9*!cm in diameter). In 67 of primary liver hepatocellular carcinoma, the tumors' size were smaller than 5*!cm in diameter in 21 cases; 35 with secondary liver tumors. RFA were performed under the guidance of ultrasonography in 43 cases, under CT in 50, under laparoscopy in 3, and 6 were performed during open surgery. All patients received ultrasonography and CT scanning of liver one month after the ablaton. The echoes of the tumors were stronger, and the area of the echo reached was larger than pre-ablation; blood flow in the tumor obviously reduced and even disappeared in sonography; CT showed that the shadow density in the tumor was diminished. Of the 102 patients, 14 underwent 18-FDG-PET imaging 30 days after the ablation, of them, 11 showed defect of radiation in the tumor, 3 showed residual locus in the tumor. 2 of the 3 cases underwent RFA again and the residual was disappeared completely, the another subject to ethanol injection because of advanced age. All the patients were followed up for 3-18 months. Except 6 patients with late metastastic liver cancer died within 1 year after RFA, the other 96 cases remained alive now, the 1-year survival rate was 94.1%. Conclusions　RFA is a new ideal therapy for liver cancer. It is safe, effective, and good tolerance with little trauma.