Abstract: Objective To study the correlation between ¹⁸F-FDG uptake and effect of small dose 5-Fu on biological behaviors of liver cancer HepG2 cells. Methods Morphological changes of liver cancer HepG2 cells were observed 4 weeks after they were cultured with 1μg/ml 5-Fu（expressed as HepG2/4P）.Then,their growth curve was plotted to calculate the doubling time of their growth.Expression of Ki67 was detected by Western blot.Uptake of ¹⁸F-FDG in vitro was detected using radioactive nuclide. Results The doubling time of HepG2 and HepG2/4P was 16.2h and 25.2h,respectively.The expression of Ki67 was 0.367±0.005 and 0.270±0.019,respectively（P＜0.05）.The uptake of ¹⁸F-FDG was lower by HepG2/4P than by HepG2（P=0.093）. Conclusion The doubling time of HepG2/4P is longer than HepG2 while the expression level of HepG2/4P is lower than that of HepG2 and the uptake of ¹⁸F-FDG is lower by HepG2/4P than by HepG2,suggesting that differences in proliferation of liver cancer cells can lead to corresponding differences in glucose metabolism,and uptake of ¹⁸F-FDG can be used as an indicator in monitoring chemotherapy and biological behaviors of liver cancer cells.