To detect the expression of telomerase subunits human telomerase reverse transcriptase, human telomerase associated protein 1 and human telomerase RNA) in gastric cancer and to examine the role that different telomerase subunits play in the gastric carcinogenesis, reverse transcription-polymerase chain reaction (RT-PCR) was used to detect telomerase subunits messenger RNA in 24 samples of gastric cancer and corresponding non-cancerous tissue. The results showed that the positive rate of hTERT mRNA from gastric cancer and corresponding non-cancerous tissues was 100 % and 25 %, respectively. The former was significantly higher than the latter (χ2 =26.4, P＜0.01). The positive rate of hTEP1 mRNA from gastric cancer and corresponding non-cancerous tissues was 100 % and 91.7 %, respectively and no significant difference was found between them (χ2 =2.1, P＞0.05). The positive rates of hTR for gastric cancer and corresponding non-cancerous tissues were both 100 % and no significant difference existed between them. It is concluded that in contrast to hTEP1 and hTR, the up-regulation of hTERT mRNA expression may play a more important role in the development of gastric cancer.