The mechanism of telomerase activation is still not clear till now. In order to understand the expressional mode of telomerase and the mechanism of telomerase activation in laryngeal carcinogenesis, we cloned a fragment of hTERT cDNA and prepared a monoclonal antibody against hTERT. We performed immuno-histochemical staining in laryngeal cancer tissues using this antibody. We found that the frequencies of hTERT positive cells were positively correlated with undifferentiation of cancer tissues and that the expression of hTERT was positively correlated with levels of c-Myc, which suggested that c-Myc might play an important role in activation of telomerase. These results revealed that overexpression of c-Myc upregulated telomerase, which in turn resulted in immortalization of laryngeal squamous cells, and this mechanism existed not only in the initiation of laryngeal carcinogenesis but also in the whole process of cancer development.