Abstract: MicroRNA (miRNA) are noncoding RNA of 21~25 nucleotides that act as posttranscriptional regulators of gene expression, it plays a multiple role in the regulation of cell growth and development. miRNA mutation or ectopia expression is associated with a variety of tumor. Ionizing radiation which has a carcinogenic or tumor suppressive effect induces changes in miRNA, miRNA expression changes induced by radiation are also cell-specific and gender-specific.