Abstract: Objective : To investigate the expression of Survivin protein, an inhibitor of apoptosis protein (IAP) family member, in normal oral mucosa, oral submucosal fibrosis (OSF) and oral squamous cell carcinoma (OSCC) o-riginating from OSF.We will also explore the clinical significance of Survivin in the carcinogenesis of OSF and the relationship between Survivin expression and clinical features of OSCC originating from OSF.Meth-ods: We used reverse transcription polymerase chain reaction (RT-PCR) and Western blot to detect the Sur-vivin mRNA and protein expression in tissues from 10 normal oral mucosal tissues, 40 cases of OSF (10 cas-es of early stage, 15 cases of moderately advanced stage, and 15 cases of advanced stage) and 42 cases of OSCC originating from OSF. Results : Survivin mRNA was not detected in normal oral mucosal epithelium.The rate of Survivin mRNA detection in OSCC originating from OSF (95.2%, 40/42) was significantly higher than that in OSF (47.5%, 19/40) ( P <0.01).No statistically significant difference was found in the rates of Survivin mRNA expression among the different stages ( P >0.05).Western blot analysis showed gradually increasing ex-pression of Survivin protein as the stage of OSF increased, which was consistent with Survivin mRNA expres-sion.For patients with OSCC originating from OSF, Survivin mRNA expression was not correlated to age, tu-mor size, tumor location or TNM stage. Conclusion : Survivin may play an important role in the carcinogenesis of OSF and may provide an index for diagnosis as well as a target for treatment.