Abstract: The amounts of urinary polyamines of 161 patients with cancer of allmentary canai were determined.The urinary polyamines in these patients were significantly higher than those in normal subjects.The putrescine,spermidine and spermine had respectively increased by 0.86 to 2.28 times,0.11 to 0.72 times and 2.76 to 5.17 times.Of the patients,88.0% to 100% had arise in one of the three polyamines while 60.87% to 80.0% in two.Between the putrescine and spermidine in the electrophoregram a histamine-like substance was detected.Whose value was also high,and 1.02 to 1.48 times higher than the normal value with a positive elevated rate of 47.06% to 60.42%.Patients' urinary polyamines were reduced as shown by repeated assay maed in 21 cases postoperatively and 2 cases after chmotherapy.The assay of urinary polyamine can be used as an auxiliary method in the clinical diagnosis and therapeutical evaluation of cancer of alimentary canal.