MicroRNAs are a set of short noncoding RNAs that post transcriptionally control the gene expression through matching with its corresponding mRNAs. The down regulated of micro RNAs may be suggested as a novel kind of “oncomirs”or “tumor suppressors,” acting an important effect in the development of carcinoma. Employing genome wide detection techniques, common erratic expression types of micro RNAs have been recognized in a wide arrangement of cancers in human, demonstrate huge potential as modern detection and predictive agents of up normality and elevation of sensitivity and specificity. The diagnosable micro RNAs in blood and the further body fluids with rise constancy supply a profuse origin for micro RNA based agents in cancer cases. In spite of the verity that a growing number of effort micro RNA agents have been determinate, the transmission of micro RNAs based agents from board to bedside as yet important treatment and control many challenges. This study will demonstrate the recent comprehensive of micro RNAs as important agents in cancer of human.