Abstract:AVO effect indicates how seismic reflection amplitude varys with offset.Under certain condition,AVO effect can be used to predict reservoir parameters and hydrocarbon anomaly.However,AVO effect hardly reflects solely reservoir parameters and hydrocarbon anomaly because it may result from many factors.The analysis of multiwave AVO effect avoid the multiple solution of prediction result,which is particularly reliable in thin reservoir condition.The research on multiwave AVO effect has been made by adopting full Zoeppritz's equation and models of thin reservoirs which have gas and no gas.The research shows that the AVO effect of P-P wave follows tuning principle whether the thin reservoir has water or gas,and that P-SV and S-S waves all exhibit obvious AVO phenomenon whether the thin reservoir has gas or not.