Objective To study the identification effect of 64 slice spiral CT on hepatic carcinoma and hepatic focal nodular hyperplasia (FNH). Methods 28 cases of patients with FNH and 24 cases of hepatic carcinoma were taken as the research object. All of the patients received 64 slice spiral CT detection to get energy spectrum series of images in arterial phase and portal vein phase and the carrier noise ratio(CNR) between lesions and liver, normalized iodine concentration (NIC), the NIC of lesions and the surrounding tissues (LNR) of liver were calculated. Results In the arterial phase, CNR of patients with hepatic carcinoma was significantly lower than that of patients with FNH and the comparison between groups was statistically significant (P<0.05). 40-50keV showed a rising trend and then decrease with the increase of energy while in portal vein phase, 40- 70keV in patients with hepatic carcinoma showed a rising trend, then showed a decreased trend and increase period of FNH leading to 40-50keV. 50-90keV decreased and then showed an increasing trend; NIC and LNR of the hepatic carcinoma (HCC) group in arterial phase and portal vein phase were significantly lower than those of FNH group and the difference was significant (P<0.05). Conclusion 64 slice spiral CT is of important clinical significance in the differentiation of hepatic carcinoma and hepatic focal nodular hyperplasia,which is of high clinical value.