Abstract: Objective: To investigate the expression of cyclin D1 in nasal sinus neoplasm and its clinical significance. Method: SABC immunohistochemical technique was used to determine the expression of cyclin D1 in 20 samples of nasal sinus carcinoma and 10 samples of benign lesion. Results: Cyclin D1 was over-expressed in all nasal sinus carcinoma, whereas no or weak expression was determined in benign lesions. The cyclin D1 integral was not correlated with age, gender, site of tumor or pathologic type（P＞0.05） but correlated with the TNM stage and histological grade（P＜0.05). Moreover, it gradually increased following the increase of stage and histological grade. There were significances between cyclin D1 integral of preliminary cases and recurrence cases（P＜0.05). Conclusion: Cyclin D1 may play an important role in tumor genesis.

Key words: Cyclin D1, Nasal sinus neoplasm, Immunohistochemisty