Hepatocellular carcinoma is one of the most common tumor in clinical practice. In recent years, various local therapies, especially radiofrequency ablation (RFA) has been proved safe and effective.The main limitation of RFA is that its therapeutic impact is significant compromised by blood flow cooling effect, especially in hypervascular HCC. Recent studies showed combined therapy of TACE and RFA can decrease the blood supply of tumor, increase ablated volume and therefore improve the outcome. However, TACE application is limited in patients who cannot tolerate this therapy due to the side effects of repeated TACE, poor liver function or previously legated hepatic artery. The present study is focus on "difficult-to-treat" HCC patients who are neither surgical candidates, nor TACE candidates. The investigators introduce the novel treatment mode that RFA followed ultrasound guided percutaneous ablation of tumur feeding arterial to treat these difficult cases and evaluate the clinical effect.