Objective To study the relationship between the expression of telomerase activity in human gastric cancer and the development of gastic cancer.Methods Telomerase activity in 45 samples from primary gastric cancer and 40 samples of "normal" gastric tissues was examined using in situ hybridization technique.Results Telomerase activity was positive in 38 of 45 gastric cancer tissues.Telomerase positive expression in advanced stage gastric cancer was 93 3%,which was significiantly higher than that in early stage(66 6%)(P