Abstract: MiR-224 is a small noncoding RNA that usually binds to response element of target mRNA through the seed sequences，leading to the suppression of translation or mRNA degradation。Recent researches indicate that miR-224 not only aberrantly expresses in multiple tumors （ hepatocellular carcinoma ，gastric carcinoma、diffuse large B—cell lymphoma，prostate cancer， colorectal cancer, etc），playing an important role in tumor suppressor or oncognen，but also has an effect on the chemosensitivity of tumor.In this article,we review recent studies about the mechanism of miR-224 in the tumor development ,progression and chemosensitivity.

Key words: microRNAs, neoplasms, genes, tumor suppressor, oncogenes, review, miR-224