Abstract：The usual traveltime seismic tomography methods are based on ray theory;however,the energy of real seismic signals comes from one Fresnel volume connect-ing source point and receiving points instead of a hypothetic ray. Mere I try to intro-duce Fresnel volume concept into seismic tomography,which results in three advan-tages:maintaining desirably the original resoluton of the given seismic data setimproving the ray illumination.increased resistance of error,namely the ray error which was caused by in-correct initial velocity field in forward tomography The advantages were demonstrated by theoretical model test. Some differencesbetween theoretical traveltimes from synthetic seismograms and computed travel-times can be observed in theoretical model design. To speak exactly,the theoreticaltraveltimes are usually lower than the computed traveltimes when rays traversehigh-velocity anomaly;but when rays traverse low-velocity anomlay,thetheoreticaltraveltimes are higher than the computed ones. As witnessed in our tests,the phenomenon will affect any seicmictomography method that is based on rays.
