Abstract:The seismic responses of site will be influenced to certain extension when seasonal frozen soil and permafrost exist. According to one-dimensional fluctuation theory,the seismic responses field of Classes I and II in permafrost and seasonal frozen soils are calculated under multifarious earthquakes by using equivalent linearization program of plane-stratum earthquake response. The influences of seismic responses in field are analyzed due to the thickness change of frozen soil layer. It indicates that in seasonal frozen regions,the peak value of ground surface acceleration decreases when seasonal frozen soil exists;and its acceleration peak value decreases with decrease of temperature of frozen soil and with increase of thickness of frozen soil. The influences of frozen soil/site of Class I are greater than that of Class II. The calculated results also show that in permafrost,the deeper of frozen soil layer is,the more decrescent of the site ground acceleration peak value for site of Class II is. However,the rule is not suitable for site of Class I. When the overlay of permafrost is thawy soil,the acceleration peak value is greater than that when the overlay permafrost changes into frozen soil.