Abstract: On the basis of abundant data of seismic profiles and velocity spectra,the authors of this paper firstly calculated and analysed the seismic interval velocity and distributive characteristics in the upper Jurassic of the Luxi Depression,Innor Mongolia;then drafted the master curves of sandstones and mudstones in the area.Thereafter,the percentages of sandstones in various intervals are estimated by using acoustostratigraphic smooth and correlation of compactions.Based on the analysis of interval velocity and interpretation of lithology,the correlative relation among the velocity,seismic facies and sedimentary facies could be comfirmed and it would provide quantitative basis for prodicting favourable facies belts in the study area.