Most seismic noise attenuation methods will reduce the data fidelity. A kind of adaptive noise attenuation scheme based on feedback mechanism is introduced in this paper. Noises in seismic data are classified into two categories: unbalanced and balanced noises. Two-step strategy is taken. The unbalanced noises are attenuated first and then the balanced noises. Two indicators NCR and SCR are established to denote the reliability of noise and signal section aiming at the two kinds of noises. The meanings of NCR and SCR are analyzed

adaptive noise feedback coefficient is designed based on the two indicators

the simultaneous enhancement of signal-to-noise ratio and fidelity is achieved. Tests demonstrate that the method is effective.