Abstract: It's significant to extract underground media information for reservoir prediction from elastic impedance. While traditional extraction methods are mostly based on least squares theory, in this paper accumulation method is brought in to extract parameters from elastic impedance. Both methods are applied on a four-layer model and part of Marmousi 2 model to extract P-wave velocity, S-wave velocity and density from elastic impedance which contains Gaussian distribution background noise and uniform distribution background noise respectively. According to the quantitative comparison, the accuracy of the two methods ale approximate. Conclusion can be drawn that accumulation method is feasible and effective to extract parameters from elastic impedance.