Abstract: 3H-angiotensin Ⅱ binding sites possessing the characteristics of a membrane recepter were identified in left ventricular myocardium membrane preparations from spontaneously hypertensive rats （SHR ） and Wistar-Kyoto rats （WKY）. The results showed that typical multisite saturation curves were obtained and KD= 4. 62±1. 92 nmol/L and Bmax =103.75±19.28 fmol/mg protcin in WKY; KD=5.18±2.14 nmol/L and Bmax = 239. 21±48. 19 fmol/mg, protein in SHR.Bmax was significantly higher in SHR than that in WKY.Meanwhile, plasma aldosterone was higher in SHR than that in WKY. There was no difference in plasma angiotensin Ⅱ between the two groups. By observing the ultramicro-structure of myocardial tissue from SHR, the cxistence of LVH were confirmed. There was changes in the ultramicrostructure of myocardial tissue in SHR.