Abstract: Objective: To analyze the changes of microRNAs (miRNAs) expression in rat cardiac hypertrophy.Methods: To understand the roles of miRNAs in hypertrophy,a rat model of cardiac hypertrophy was established with abdominal aortic constriction (AAC).Real-time quantitative PCR was used to detect the changes of miRNAs expression in myocardium.Results: The heart weight/body weight,Nppa and myh7,the coding genes of atrial natriuretic peptide and β-myosin heavy chain (which were the markers of cardiac hypertrophy) were significant up-regulated on week 1 after AAC,it was meant the success of cardiac hypertrophy model.One week after aortic banding,miR-1,miR-133,miR-181a and miR-499 were significantly down-regulated,whereas miR-199a was up-regulated.Four weeks after AAC,miR-21,miR-24 and miR-214 were up-regulated,whereas miR-181a was significantly down-regulated,while miR-23a,miR-133,miR-145,miR-199a and miR-499 were unchanged.Conclusions: The expression of miRNAs was changed in rat cardiac hypertrophy,the changes of miRNAs maybe played an important role in regulation of cardiac hypertrophy pathological process.