The　mechanism　of　passive　piles　to　keep　out　the　soil　layers　that　move　laterally　is　mainly　the　soil　arching　effect　between　piles;　this　effect　is　a　phenomenon　to　transfer　stresses　from　a　yielding　mass　onto　the　adjacent　stationary　part　of　the　soils.　The　geotechnical　analysis　software　package　named　Plaxis　tunnel　3D　1.2　is　used　to　study　the　mechanism　and　behavior　of　soil　arching　effects　in　passive　piles　due　to　surcharge　loads　using　three　dimensional　finite　element　method.　Limitations　of　two-dimensional　finite　element　analysis　used　by　former　researchers　for　soil　arching　effect　are　discussed　in　brief.　Taking　into　account　of　the　effect　of　passive　pile　displacement,　the　geotechnical　two-dimensional　finite　element　software　Plaxis　8.2　is　used　to　study　the　behavior　of　soil　arching　effect.　And　the　effects　of　different　factors　on　soil　arching　effect　and　the　ratio　of　loads　on　piles　to　that　on　soils　are　depicted,　such　as　soil　properties,　piles　spacing　ratio,　passive　pile　displacement,　and　the　interface　behaviors　between　pile　and　soils.