A geophone-based experimental system is designed to analyze landmines’impact on earth surface acoustic impedance.Loudspeaker is used to insonify a swept sine tone over the soil.Sound level meter and geophone are respectively adopted to measure the applied acoustic pressure level and the induced vibration velocity at the surface.The experimental data shows that the ratio of surface acoustic impedance off-to-on mine appears two peak values at 72Hz and 140Hz.Constructive interference theory and resonance mechanism between the mine and the soil on top of its are used to explain such phenomenon.The results indicate that landmines decrease the surface acoustic impedance within a wider frequency range and the presented system can be used to further experimental study of acoustic landmines detection.