Abstract: Objective 　To investigate the expression of PAR1 in nasopharyngeal carcinoma (NPC) and it s significance. Methods 　Immunohistochemical (SP method) was used to detect PAR1 expression in 28 ca2 ses of benign nasopharyngeal tissues and 61 cases of NPC. The relationship between the expression of PAR1 in NPC and the clinical parameters was ret rospectively analyzed. Receptor expression on protein and mRNA level was evaluated in two human NPC cell lines (CNE22 and CNE21) by Western Blot, and RT2PCR. Results 　Of 61 cases of NPC examined, PAR1 expresses in 48 cases ; of 28 cases of nasopha2 ryngeal benign lesions examined, PAR1 expressed in 10 cases. The rate of PAR1 expressed in NPC was higher than that in the nasopharyngeal benign lesions ( P < 0. 01) . The more malignant and metastasis cell line (CNE22) expressed higher mRNA and protein level of PAR1 than the lowly malignant and metas2 tasis cell line (CNE21) by RT2PCR and Western Blot . Conclusion 　The expression of PAR1 is correlated with carcinogenesis、growth pattern、clinical staging、malignancy of NPC. PAR1 may cont ribute to the malignant phenotype and biological behavior in NPC.