Objective To investigate the expression and clin. significance of microRNA-34 a( miR-34 a) and microRNA-21( miR-21) in cervical cancer( CC) patients. Methods The expression levels of miR-21 and miR-34 a in peripheral plasma were measured by qRT-PCR. The data were statistically analyzed using SPSS 17. 0 software. The two groups of measurement data were compared by t test,and the diagnostic performance was evaluated by the receiver operating curve( ROC).Results The expression level of miR-21 in CC group was significantly higher than that in the control group( P < 0. 01) and the expression level of miR-34 a was significantly lower than that in the control group( P < 0. 05). The expressions of miR-21 and miR-34 a were correlated with clin. stage and lymph node metastasis( P < 0. 01). The area under the curve( AUC) of miR-21 was 0. 881,and the AUC of miR-34 a was 0. 911,both of which had higher diagnostic potency. Conclusion MiR-21 may be a tumor-promoting gene,miR-34 a is a tumor suppressor gene,miR-21 and miR-34 a are involved in the development of cervical cancer,and have important clin. value in the diagnosis and monitoring of cervical cancer.