Objective: To investigate the clinical diagnostic value of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in the peripheral blood of patients with oral squamous cell carcinoma (OSCC). Methods: Fluoresence quantitative RT-qPCR was used to detect the expression of MALAT1 in the preoperative peripheral blood samples and paired postoperative tumor tissues of patients with OSCC. Results: The mean expression level of MALAT1 in peripheral blood of patients with OSCC was significantly higher than that of healthy volunteers (1.845±0.142 vs.0.642±0.090

P<0.001). The expression level of MALAT1 in peripheral blood was positively correlated with the paired tumor tissues with a correlation coefficient of 0.783 (P<0.001). The expression level of MALAT1 in peripheral blood was correlated with tumor TNM stage (P=0.001) and cell differentiation (P=0.010). The area under the ROC curve of MALAT1 for the diagnosis of OSCC was 0.892.When the cutoff value was 0.788

the diagnostic sensitivity and specificity of MALAT1 were 85%and 81%respectively. Conclusion: MALAT1 has potential clinical value of diagnosing OSCC

and is expected to be a serum molecular marker for the diagnosis and prognosis of OSCC.