〔Abstract〕 To explore the value of T1 mapping techniques in the evaluation myocardial fibrosis in 23 patients with hypertrophic cardiomyopathy( HCM) and 18 patients with dilated cardiomyopathy( DCM),and to study the correlation between the native T1 value and cardiac function. The native T1 values in HCM group,DCM group and control group were statistical significance [( 1 318. 4 ± 44. 7) ms,( 1 353. 7 ± 56. 9) ms and( 1 267. 0 ± 24. 3) ms,P<0. 05) ]; the native T1 value of the left ventricular myocardium in HCM and DCM patients was negatively correlated with the LVEF( r =-0. 488,P<0. 05; r =-0. 659,P<0. 01). The study showed that T1 mapping evaluated the myocardial fibrosis of HCM and DCM noninvasively. The myocardial fibrosis shown by the native T1 value of the left ventricular myocardium was negatively correlated with cardiac function in patients with HCM and DCM.