震水位阶所反演的应变变化以1984年5月21日南黄海6.2地震为例，计算距震中175km的苏20井同震水位阶变的应力变化，结果表明，地震造成的应变变化与同具有相同的数量级，地震引起的同震水位阶代表了地震造成的应力（应变）大小，具有动力学含义。

This paper quantitatively discusses that static stress changes at the epicenter and nearby area after different types of the earthquake occurred by establishing concept model. For example, as the southern yellow sea earthquake of May 21th ,1984 , the stress changes of coseismic water level offsets recorded by the water level of Jiangsu 20th well about 175Km from the epicentral were calculated. The results show that : The stress changes caused by earthquake and the stress changes inversed by coseismic water level offsets are having the same order of magnitude. The water level offsets caused by earthquake can reflect  the magnitude of the stress produced by earthquake and it has dynamical meanings.