Telomeric repeat binding factor 1 plays pivotal roles in telomere protection and maintenance in mammalian cells. In this article, the expression of telomeric repeat binding factor 1 protein in nonsmall cell lung cancer with human telomerase reverse transcriptase positive is investigated, and the relationship between the telomeric repeat binding factor 1 and clinic factors is analyzed. The expressions of human telomerase reverse transcriptase were detected by immunohistochemistry. The levels of telomeric repeat binding factor 1 protein were measured by Western blot. In all, 72% (36/50) patients showed human telomerase reverse transcriptase positive. Telomeric repeat binding factor 1 expression of cancer tissues and paired noncancerous tissues in 30 cases of human telomerase reverse transcriptase positive was 0.552 +/- 0.329 and 0.654 +/- 0.476, respectively (P < .05). No significant difference in telomeric repeat binding factor 1 protein expression was observed among sex, clinical stages, pathological subtypes, and lymph node metastasis. The results indicated that down-regulation of telomeric repeat binding factor 1 expression appeared in lung cancer tissue, and no correlation was found between telomeric repeat binding factor 1 expression and clinicopathologic factors.