Objective：To assess clinical value of 320-detector row CT perfusion imaging（CTPI） in evaluating the activity of residual hepatocellular carcinoma（HCC） within 1-3 months after transcatheter arterial chemoembolization（TACE）. Methods：Totally 36 pa－tients with HCC underwent upper abdominal perfusion scan after receiving TACE and digital subtraction angiography（DSA） within one week after CT perfusion scan. Hepatic perfusion parameters were acquired by CT perfusion analysis software. Effects of CTPI on activity of residual HCC after TACE were evaluated by using DSA as a golden standard. Radiation doses of 320-detector row CT per－fusion scan were analyzed. Results：CT perfusion scan was conducted for 36 times and 43 lesions were assessed. Totally 34 active le－sions were detected by CT perfusion scan，with diagnosis accuracy of 95.35％ approximate，sensitivity of 100.00％，specificity of 81.80％ approximate，positive predicative value of 94.12% approximate，negative predicative value of 100.00%，positive likelihood ra－tio of 5.5，negative likelihood ratio of approximate 0 and Youden’s index of approximate 81.80％ in detecting the residual blood sup－plies. There were differences in active focal hepatic arterial flow，portal flow and hepatic arterial perfusion index of tissues after TACE compared with those of normal hepatic tissues. Perfusion scan with lower parameter（100 kV，100 mA） had lower radiation dose than the conventional upper abdomen enhanced scan while that with higher parameter（100 kV，200 mA） only had slightly higher radiation dose. Conclusions：320-detector row CTPI can well display the activity of residual HCC after TACE. It is very useful for postoperative follow-up after TACE.