[en] Radiopharmaceutical of ¹⁸F-FHBG was synthesized and recombinant expression plasmid pLXSN-tk was constructed. The nude mice sub-skin model transplanted with human liver cancer was constructed by subcutaneous implantation of cultured the BEL-7402 liver carcinoma cell lines into the two sides axillary fossa nude mice. The left tumors were used as the control, while the right tumors were used as the experiment group, with the cancer cell being transfected by the pLXSN-tk. PET images were taken at 10, 30, 50, 70, 90, 110, 130, 150, 170, 190 and 210 min after ¹⁸F-FHBG injection via the tail veins. The results show that the uncorrected radiochemical yield of ¹⁸F-FHBG was 4%-10% and the radiochemical purity was over 95%. The ¹⁸F-FHBG PET images indicated that ¹⁸F-FHBG uptake of the control did not increase obviously, whereas high activity was observed in the experiment group 50-210 min after ¹⁸F-FHBG injection. ¹⁸F-FHBG uptake of the experiment group increased gradually to 19.772 kBq·mL^-1 150 min after ¹⁸F-FHBG injection, where the experiment/control tumor ratio was peaked at 4.99. The results indicated that ¹⁸F-FHBG PET imaging of HSV1-tk expression in tumors can be used to monitor, in living animals, and expression of theoretical gene. (authors)