Observed time-varying properties of the Earth’s crust after large earthquakes are correlated with the increase in stress. postseismic slip of the great earthquakes can give rise to temporal changes in the medium either due to strong ground motion damaging near-surface sediment layer or stress perturbations modulating crack density and/or fluid movement at depth. Such time-varying crustal properties can result in a fractional change in seismic wave attenuation and velocity. The spatial and temporal variations of coda attenuation (Qc) were studied in the source region of the Fariman (Mw 6, 2017) earthquake. The Qc values were determined from the amplitude decay rate of the S-wave coda in narrower overlapping frequency bands in the range f=2–32 Hz using the lapse time window 15s, based on a single back-scattering model for regional earthquakes recorded in a period from April 2017 to May 2017, including postseismic period. The reduction in Qc following this event indicates high pore fluid saturation within the fractured fault zone due to the postseismic fluid redistribution. Approaching the earthquake, we observed clear variations in the seismic wave propagation properties.