〔Abstract〕 Objective To explore the value of18F-FDG PET/CT dynamic imaging in the diagnosis of primary liver cancer and liver metastases. Methods In this study, the data of 94 patients with hepatic malignant lesions [hepatocellular carcinoma group(25 cases), cholangiocellular carcinoma group(27 cases), and liver metastases group(42 cases)] imaged by whole-body dynamic18F-FDG PET/CT were used as the research subjects, and the methods of(ANOVA) and subjects′ working characteristic curves(ROC) were applied to examine the patients with liver malignant tumours of different pathological types SUVmax, MRFDG, TBR and dmaxwere statistically analysed as imaging features. Results Among 94 patients, the differences in SUVmax, MRFDG, TBRSUV (max ) and TBRMRFDGwere statistically significant in the hepatocellular carcinoma, cholangiocellular carcinoma and hepatic metastasis groups(SUVmax: F=48.773, P<0.001; MRFDG: F=26.334, P<0.001; TBRSUV (max ): F=41.314, P<0.001; TBRMRFDG: F=20.821, P<0.001).The AUCs for the differential diagnosis of primary hepatocellular carcinoma and hepatic metastases for SUVmax, MRFDG, TBRSUV (max ), and TBRMRFDGwere 0.836, 0.851, 0.827, and 0.847, respectively.There was a positive correlation between SUVmax, MRFDG, and the hepatic malignant lesions′ There was a positive correlation between SUVmax, MRFDGand the maximum diameter dmax(SUVmax: r=0.4, P<0.05; MRFDG: r=0.2, P<0.05), and the difference was statistically significant. Conclusion18F-FDG PET/CT dynamic imaging has good differential diagnostic efficacy in different pathological types of liver malignant tumors. There is a positive correlation between SUVmax, MRFDGand dmaxin different pathological types of liver malignant tumors.