MicroRNAs(miRNAs) are endogenous short non-coding RNAs,and play a pivotal role in regulating a variety of cellular processes,including proliferation and apoptosis,both of which are cellular responses to radiation treatment.In response to radiation,multiple miRNAs show altered expression,which act as oncogenes or tumor suppressors.Recent evidence has also shown that some miRNAs have radiotherapy sensitization or radiation resistance role in malignant tumors.This review focuses on analysis of these characteristics and mechanisms of miRNAs,and will provide some insight into the therapeutic application of radiation.