Becauseofitspotentialapplicationsinagriculture,environmentmonitoringandsoon,wirelessundergroundsensornetwork(WUSN)hasbeenresearchedmoreandmoreextensivelyinrecentyears.ThemainandmostimportantdifferenceofWUSNtoterrestrialwirelesssensornetwork(WSN)isthechannelcharacteristics,whichdeterminesthedesignmethodologyofit.Inthispaper,thepropagationcharacterofelectromagnetic(EM)waveinthenearsurfaceWUSNisanalyzed,aswellasthepathlossmodelofitisgiven.Inaddition,theinfluenceofhuman'sankletothechannelcharacteristicsofnearsurfaceWUSNisinvestigatedbyelectromagnetictheoryanalysis,simulationandexperiment.AnovelpathlossmodelofnearsurfaceWUSNwhichtakestheinterferenceofhuman'sankleintoconsiderationisproposed.ItisverifiedthattheexistingofhumanabovetheWUSNsystemmaycauseadditionalattenuationtothesignalofnearsurfaceWUSNwhichpropagatesaslateralwavealongtheground.Moreover,therelationoftheattenuationandoperatingfrequencyisdeduced,whichgivesareferencetoextendthefrequencybandappliedinWUSN.
