Abstract: Objective To observe the expression of TGF-β1,TGF-β2, Smad7,key members of TGF-β/Smad signal transduction pathway, and it's downstream transcription factor RUNX3 in Nasopharyngeal Carcinoma(NPC), and analyze their internal relationship and their relationship with the clinicopathologic parameters of NPC patients. Methods The protein levels of the key members of TGF-β/Smad signal transduction pathway in 50 nasopharyngeal carcinoma and 20 chronic nasopharyngitis tissues were investigated with immunohistochemical SP method. Results The positive expression rate of TGF-β1、TGF-β2、Smad7 and RUNX3 in 50 nasopharyngeal carcinoma was 42%、70%、40% and 56% respectively, and 0、100%、0、100% in 20 chronic nasopharyngitis tissues. Each of these four factors has statistical difference between the two groups(P＜0.05). The expression of TGF-β1 and Smad7 was correlated with tumor's clinical stage and local infiltration or metastasis (P＜0.05), however,TGF-β2 and RUNX3 were not(P＞0.05). TGF-β1 and Smad7 were positively related(rs=0.6286, P＜0.05),and TGF-β2 and RUNX3 too (rs=0.4748, P＜0.05). None of these four factors has any correlation the gender, age and histological grades(P＞0.05). Conclusion In NPC, TGF-β1 and Smad7 were up-regulated expressed and positively related, and they may take part in the progression and metastasis of the cancer together; oppositely, TGF-β2 and RUNX3 were down-regulated and also positively related, which may be beneficial factors against NPC and had some cooperativeness. The mechanism of their interactions deserves further study.