Telomeres play a vital role in maintaining the integrity of the genome. Mammalian telomeres are certainly transcribed into telomeric repeat-containing RNA (TERRA). This Long non-coding RNA participates in the regulation of telomere length and telomerase activity. As reported, lncRNAs play important roles in gastric cancer progression. Telomerase and its major catalytic subunit (hTERT) are upregulated in most cancers, including gastric cancer. RNA interference (RNAi) has been proven to be a powerful tool for gene knockdown and hold good promise for the treatment of human diseases including cancer. In this study, we investigated the effect of hTERT repression on the TERRA expression and telomere length in multiple passages.