本文就原发性高血压大白鼠（ＳＨＲ）和正常京都纯种大白鼠（ＷＫＹ）作对照，测定其胸主动脉的管径、厚度、应力－应变和断裂时的相对伸长度，在拉格郎日（Ｌａｇｒａｎｇｉａｎ）意义下讨论应力应变，并按冯元桢－维拉伸理论，从实验得出经验公式：ｄＴ／ｄλ＝α（Ｔ－β）＝αＴ－Ｅ０，以确定高血压和老龄化血管生物力学性能的变化。发现：不仅京都鼠血管的相对伸长率大于高血压鼠，而且从各年龄观察，幼龄的血管相对伸长率大于老龄者，高血压和老龄者的血管弹性模量相对大；在低应力区时，高血压和老龄化的胸主动脉弹性差，弹性模量大，刚度大；

We tested the thoracic aortas of spontaneously hypertensive rats(SHR)and Wistar Kyoto Rats(WKY)about diameter,thickness,strain-stress and relatively stretch length at fragility time.According to Lagrangian meaning and straight stretch theory of Feng Yuanzhen, we discussed the strain-stross and got the experience fomula:dT/dλ=α(T+β)=αT+ E0,which was used to assess the vascula's boimechanics of SHR and WKY in hypertension and aging.It is show that not only the vesscle's relatively stretch length of WKY is more than SHR'S, but also young than old(P<0.01,P<0.05).The vasculas of SHR and aging have higher elastic modulus.Always,the elastic protein and smooth muscle play an important role at the lower strain and the collagen fiber at higher strain.It is considered that the thoracic aortas in SHR and aging having higher elastic modulus are due to the decline in elastic protein.