AIM: To investigate the difference of amino acid uptake between normal and cancerous colon tissues.METHODS: Sixteen patients with colon cancer were enrolled in our study. Blood samples were taken during operations, serum amino acid concentrations of blood from cancerous or normal colon were analyzed. Amino acid uptake rate was calculated by the A-V difference and evaluated statistically.RESULTS: Except for methionine, the uptake rate of amino acids in cancer was higher than that in normal colon (25.01% vs-2.29%, P＜0.01). The amino acid uptake rate did not correlate to the size of tumor mass (P＞0.05). There was no statistical significance in the amino acid uptake rate according to the Dukes stage, though it was higher in patients with Dukes stage C or D than that with Dukes stage B (P＞0.05).CONCLUSION: Abnormal synthetic metabolism of colon cancer may contribute to its higher amino acid uptake rate than that of normal colon.