Atherosclerosis is one of the comprehensive diseases which caused by several factors such as inflammation,innate immunity and lipid infiltration. MiRNA comprise a novel class of endogenous,small RNA of 18～24 nucleotides that regulate the expression of target gene at posttranscriptional level. MiRNAs’ dysfunction is involved in all the stages of atherosclerosis. Among these miRNAs,miR-145 can affect the proliferation,migration and phenotype transformation of cells and participate in atherosclerosis,through regulating the target gene downstream.