Accumulating evidence has shown that miRNAs are aberrantly expressed in human gastric cancer and crucial to tumorigenesis.Herein, we identified the role of miR-148a in gastric cell proliferation.miR-148a knockdown inhibited cell proliferation in gastric cancer cell lines.Conversely, miR-148a overexpression promoted cell proliferation and cell cycle progression.p27, a key inhibitor of cell cycle, was verified as the target of miR-148a, indicating miR-148a might downregulate p27 expression to promote gastric cell proliferation.Moreover, we confirmed that miR-148a expression was frequently and dramatically downregulated in human advanced gastric cancer tissues, and observed a good inverse correlation between miR-148a and p27 expression in tumor samples.Thus, our results demonstrated that miR-148a downregulation might exert some sort of antagonistic function in cell proliferation, rather than promote cell proliferation in gastric cancer.