Matsushima, J. and Nishizawa, O., 2010. Difference image of seismic reflection sections with highly dense spatial sampling in random heterogeneous media. Journal of Seismic Exploration, 19: 279-301. According to the Nyquist sampling criterion, it is redundant to deploy a smaller sampling interval than the Nyquist sampling interval. However, we show the possibility of utilizing a highly dense deployment of source/receivers when applying seismic reflection methods in random heterogeneous media. We consider a seismic waveform consisting of scattered waves generated by random isotropic heterogeneity, which is a noise-like wave field caused by multiple scattering of seismic waves. The final section contains disturbance due to the multiple-scattering effects in small-scale heterogeneities that do not satisfy the assumption of migration theory based on single scattering. Our numerical experiments indicate that the highly dense spatial sampling does not improve resolution of the section when the subsurface structure contains random heterogeneity regardless of the relationship between the spatial sampling interval and the characteristic size of heterogeneities, even if the interval of spatial sampling becomes shorter than the Nyquist sampling interval. However, we found the existence of a small but significant difference between two sections generated with adequate sampling. This small but significant difference is attributed to both the truncation artifact and NMO-stretch effect which cannot be practically prevented during data acquisition and processing. We show that this small difference is dependent on the characteristic heterogeneity size, indicating that difference images have the possibility of estimating the characteristic size of heterogeneities by differentiating two sections with different adequate spatial sampling.