Background: Tumorigenesis in nasopharyngeal carcinoma (NPC) is closely related with Notch singnal, however, the underlying mechanisms of its actions are poorly known.Therefore, its very important to clearify the effective mechanism of Notch singnal on NPC development and progression.Methods: 52 biopsy specimens of clear pathological diagnosis with NPC and different cell lines were treated by immunohistochemical techniques and RT-PCR.The expression of NIC was examined.Results: NIC were detected in the different cell-lines by RT-PCR and immunocytochemical staining, the apparent expression for NIC was observed in high degree differentiated CNE 1 cell-lines.The NIC expression in NPC was significantly higher in comparison with that in chronic nasopharyngitis (P<0.05).The NIC expressions in NPC were positively correlated with differentiated degree (P<0.05), while no significant differences were observed in sex and age (P>0.05).The NIC expressions in undifferentiated NPC were positively correlated with lymphocyte but in differentiated NPC this expressions were positively at cancer cells and located in cell membrane, cytoplasm and nucleus.Conclusions: Notch signaling participate in the occurance of non-keratin naspharyngeal carcinoma, the notch-1 expression is positively correlated with the differentiated deree of NPC .