Aim of the work: there are many types of biomarkers (DNA biomarkers, RNA biomarkers and protein biomarkers). They have a pivotal role in early detecting of oral cancer. In this review, we aimed to summarize the potent plasma biomarkers which have been reported to have pivotal role in the detection and diagnostic different types of oral cancer. Methods: an electronic search in MEDLINE was conducted through PubMed using this search strategy (Plasma biomarker or plasma indictors) and (Oral cancer or oral tumor or oral squamous cell carcinoma). The search resulted in 158 eligible study and finally 10 potential articles were included in this systematic review. Results: in general, 9 articles used oral squamous cell carcinoma (OSCC) while, only one study used gingival squamous cell carcinoma as a type of oral cancer in order to evaluate the potential of biomarker to detect oral cancer. In eight articles microRNAs were predominantly used as potent biomarkers, different types of microRNAs were used. Plasma hsa-miR-542-3p recorded potential performance as biomarker in diagnosis of OSCC with AUC 0.82. Down regulation of hsa-miR-542-3p were correlated with increasing of surviving expression in OSCC. Conclusion: we can conclude that plasma microRNAs biomarkers occupied wide scope of the included studies in this review and could be serve as potent and sensitive biomarkers (especially plasma miR-125b expression and combination of miR-196a and miR-196b) for prognostic and diagnostic different types of oral cancer.