Abstract: 4D seismic is a dynamic monitoring technology for oil reservoir based on repeating 3D seismic survey.In the exploitation of oilfield,seismic amplitude anomalies caused by container layer attribute,frequency variation and the time delay of reflection lineups can all be used as 4D seismic monitoring parameters.Because there are usually many errors in stacked data,such as,imprecise dynamic correction in velocity,waveform distortion caused by normal moveout correction stretching,static correction residual,and waveform difference in CDP gathering,they influence the feature of 4D seismic anomaly from stacked seismic data,and cause indetermination and difference in explanation.To solve this problem,we tried to study the attribute of pre-stack seismic data,which is to interpret the response of injected steam in 4D seismic region qualitatively with instantaneous frequency and its gradient,frequency that attenuated 80%,peak frequency,maximum amplitude,and total energy.