The variations of elastic parameters and attenuation of rock under deformation are of great importance for a number of geophysical problems. Here, we estimate elastic parameters and their evolutions during laboratory rock deformation experiments, while developing a Monte-Carlo full-waveform fitting method. The transducer-transducer one-source one-station active seismic data of dry and water-saturated samples are obtained from Zaima and Katayama (2018, https://doi.org/10.1029/2018JB016377). The synthetic seismic data are modeled using the spectral element method. We first performed a trial-and-error estimate of the boundary conditions in order to suppress its influence on waveform matching. The synthetic seismic data are generated using equivalent homogeneous models with different combinations of elastic and anelastic parameters. We then compared the synthetics with the laboratory experimental data. Based on these comparisons, we obtain the time-lapse variations of seismic velocities and attenuation of rock samples during deformation, which are then interpreted as crack development. Our simultaneous estimation of elastic and anelastic parameters allowed us to detail the dynamics prior to the rock failure.