Despite　high　pressure　grinding　rolls　(HPGR)　have　been　widely　used　in　mining　industry　during　the　past　decades,　there　are　limited　systematic　quantifications　on　the　properties　of　the　particles　after　comminution.　Furthermore,　the　influence　of　micro-cracks　on　gold　ore　leaching　has　not　been　further　investigated.　Gold　ore　samples　were　subjected　to　two　different　open-circuit　comminutions:　conventional　jaw　crusher　and　HPGR.　Particle　size　distribution　was　measured　and　the　fractal　dimension　based　on　fractal　theory　was　obtained.　Combined　with　scanning　electron　microscopy　(SEM)　and　stereomicroscopy,　particle　spherical　indices　and　micro　crack　properties　were　further　explored.　The　results　show　that　HPGR　produced　higher　proportion　of　fines　and　less　uniformity　in　comparison　with　the　jaw　crusher,　reflected　by　the　larger　fractal　dimension.　There　was　a　marked　increase　in　spherical　indices　from　HPGR　in　9.5-4.0　nun　size　fraction.　Through　the　quasi-hydrostatic　pressure,　more　micro-cracks　were　generated　in　the　HPGR　products,　resulting　in　enhanced　infiltration　of　leaching　reagent　and　gold　recovery　in　full-slime　and　heap　cyanide　leaching.　This　paper　highlights　the　importance　of　the　effective　micro-crack　formation　and　proposes　a　leaching　kinetic　model　for　further　prediction　of　leaching　cycle.