In this study,both records of a digital accelerometer and a seismograph at a far-field station for the 2008 Ms8.0 Wenchuan earthquake were analyzed,and a pulsive noise model for acceleration record was found.By comparing with the result of a rotary-table tilt test,we concluded that the noises in the acceleration records were caused by ground tilt as a result of rotational ground motion.We analyzed the key noises that may cause baseline offset,and proposed a baseline-correction scheme for preserving the long-period ground motion in accordance with specific pulse positions.We then applied this correction method to some near-field strongmotion acceleration records.The result shows that this method can obtain near-field ground displacements,including permanent displacements,in agreement with GPS data,and that this method is more stable than other methods.