Abstract: Objective To investigate the change of CDK4 expression in oral squamous cell carcinoma（OSCC） and its prognostic significance. Methods Archival pathological specimens consisted of 48 cases of oral squamous cell carcinoma. All the cases underwent surgical operations and were classified into 2 groups:24 cases with neoadjuvant chemotherapy and 24 cases with surgery alone. Histological specimens for diagnosis obtained from diagnostic biopsy and surgical operations underwent immunohistochemical staining for CDK4 protein. Labeling index（LI） was presented by the percentage of positive cells,and change of CDK4 LI between biopsy and surgical operations was examined for association with survival. Results Decrease of CDK4 LI significantly correlated with favorable survival outcome in the cases with surgery alone（P＜0.005）. Conclusion The change of CDK4 expression may have prognostic significance in OSCC.