In this work, glucose concentration in gastric cancer cell was determinaed based on a coupled enzyme catalyzed reaction. glucose oxidase (GOD) reacted with glucose to form gluconic acid and H2O2. In the presence of horseradish peroxidase (HRP), the H2O2 then reacted with 10-acetyl-3,7- dihydroxyphenoxazine (ADHP) in a 1:1 stoichiometry to generated the fluorescent products, resorufin. So that, the glucose concentration assay could be performed by fluorometric analysis resorufin. Glucose solution or Gastric cancer cells lysate were catalyzed and detected by epi-fluorescence microscopy in a quartz capillary fluorometer cell. The fluorescence intensity were analysis by the MetaMorph Software. The linear relationship of the glucose concentrations covered a range of 1.00×10-8-1.00×10-5 mol/L with a correlation coefficient of 0.9994. LOD was 5.30×10-9 mol/L(cL = ksB/b). The glucose concentration in cancer cells lysate was 8.03×10-6 mol/L (n =4).