Abstract:The tough problem of geological property of seismic complex waves has not been well solved in seismic data interpretation. Synthetic waveforrn tracing method for analysing the geological property of seismic complex waves is presented to ascertain the geological property of thin sand and shale interbeds in Songliao basin. There are five distinguishable characteristic interfaces in synthesizing seismograms including complex waves, in which interface C is a dominant one that produces seismic complex waves. The interbeds between interface C and interface D are major ones which produce seismic complex waves. Hence, the correct depth of interface C is the key to reasonable correlating the seismic complex waves with the corresponding beds in borehole;and it is of great irnportance to good correlation of seismic horizons with the corresponding geological horizons and to lithology prediction using seismic complex waveforrns. It has been illustrated that this method results in good correlation of seismic informations with the corresponding geological inforrnations, the solution of some tough geological problems and quite satisfactory exploration effect in the Songliao basin.