Currently, circulating tumor cells (CTCs) has received widespread attention in the non-invasive cancer diagnosis and monitoring field. Studies have confirmed the important roles of miR-543 in cancer occurrence including gastric cancer. This study we aimed to investigate whether miR-543 could be used as a marker for CTCs detection in gastric cancer patients. Previous study suggested the high expression of miR-543 in gastric cancer tissue and cells, in the present study; we first confirmed the role of miR-543 in gastric cancer progress by using miR-543 inhibitor. CCk-8 and transwell assays were applied for cell proliferation, cell invasion and migration detection respectively. In addition, we determined the expression level of miR-543 in mononuclear cells (MNCs) from peripheral blood by using quantitative real-timepolymerase chain reaction (qRT-PCR). Moreover, the receiver operator characteristic curves (ROC) were constructed. Our results suggested that inhibition of miR-543 notably suppressed gastric cancer cell growth, invasion and migration. Compared with the healthy controls, the expression level of miR-543 significantly increased in MNCs from gastric cancer. The area under the ROC curve was 0.796 +/- 0.0763. In conclusion, our results indicated that miR-543 may be used as a novel bio-marker for CTCs detection in gastric cancer patients.