Objective: To investigate the expression and significance of NF-κB in oral squamous cell carcinoma and paracancerous tissues. Methods: Cancerous and paracancerous tissues about 5 mm outside the tumor boundary were cut from 47 patients with OSCC. NF-κB expression in these tissues were detected by the immunohistochemical SP method and compared with that in 32 normal oral mucosa tissues. Results : The average optical density (OD value) of immunohistochemical-positive cells in cancer tissues and paracancerous tissues was higher than that in normal tissues, and the difference was statistically significant (P < 0.001). There was no significant difference in the OD values between cancer tissues and paracancerous tissues (P=0.356). The rate of NF-κB positive expression in cancer tissue and paracancerous tissue was significantly higher than that in normal mucosa tissue, and the difference was statistically significant (P < 0.001). There was no significant difference in the rate of NF-κB positive expression between cancer tissues and paracancerous tissues (P=0.117), but the rate of moderate-to-strong positive expression in cancer tissues was significantly higher than that in paracancerous tissues (P < 0.001). Conclusion NF-κB may be involved in the development of OSCC.