Through　the　column　leaching　experiments　of　low　grade　gold　ore　crushed　by　conventional　jaw　crusher　and　high　pressure　grinding　rolls　(HPGR),　the　influences　of　coarse　particles　processed　by　two　different　comminuting　methods　on　the　leaching　rate　were　studied.　Combined　with　the　characteristics　of　products　and　microscopic　analyses　technology,　the　mechanism　of　HPGR　method　in　the　treatment　process　of　gold　ore　was　discussed　furthermore.　The　results　show　that　the　products　of　HPGR　are　finer　and　containing　richer　micro　cracks　on　particle　surface　and　have　higher　saturated　water　content　than　that　of　conventional　jaw　crusher.　HPGR　can　play　a　significant　role　in　strengthening　the　penetration　effect　of　heap　leaching　which　can　help　to　improve　the　leaching　rate　of　gold　ore　at　the　same　time.　Under　the　same　conditions,　gold　leaching　rate　of　HPGR　method　can　be　improved　by　3.5%-6.8%,　meanwhile,　the　consumption　of　leaching　solution　is　decreased　by　3.2%-11.3%.　©　2016,　Science　Press.　All　right　reserved.