Objective To investigate the therapeutic effect and the immune function impacts of high intensity focused ultrasound(HIFU) for the treatment of hepatocellular carcinoma.Methods Twenty-five cases with primary liver cancer and 6 cases with metastatic liver cancer were treated with HIFU.The clinical symptoms,AFP levels,color Doppler ultrasound detection,CT and changes of T-cell subsets ( CD3 +,CD4 +,CD8 +,CD4 +/CD8 + ) were recorded before and after treatment.Results After HIFU treatment,among 31 patients,the clinical remission rate was 89.7％ ( 25/29 ).AFP was decreased in 83.3％ ( 15/18 ) of the patients.Color Doppler showed reduced tumor sizes and reduced or disappeared blood supply in most of the patients.CT scan displayed that the density of the target region was decreased and necrosis of the lesions occurred.The percentage of CD3 + and CD4 + cells and the ratio of CD4 +/CD8 + were significantly increased after a period of treatment( P ＜0.05 ).The proportion of CD8 + cells was decreased significantly after a period of treatment ( P ＜ 0.05 ).Conclusion HIFU is an effective technique for the treatment of hepatocellular carcinoma.Meanwhile,it can improve human immune function to certain extend.