The　strength　and　the　descending　stage　of　stress-strain　curve　of　concrete　present　obvious　discreteness　and　randomness,　and　the　aggregate　spatial　distribution　pattern　turns　out　to　be　an　important　influencing　factor.　The　purpose　of　this　study　is　to　obtain　the　statistical　property　of　the　strength　and　the　descending　stage　of　stress-strain　curve　of　concrete.　The　meso-scale　mechanical　model　and　method　were　established,　in　which　the　concrete　was　assumed　to　be　composed　of　aggregate　particles,　mortar　matrix　and　the　interfacial　transition　zones　between　the　former　two　phases.　Furthermore,　the　uniaxial　compressive　mechanical　behavior　of　64　sets　of　concrete　with　different　aggregate　distribution　patterns　was　studied　numerically,　and　the　discreteness　of　concrete　strength　and　softening　curve　was　analyzed　statistically.　The　results　indicate　that:　(1)　both　the　compression　strength　and　the　softening　curve　of　concrete　of　different　aggregate　distribution　obey　the　Weibull　distribution;　(2)　the　discreteness　of　the　stresses　in　the　softening　curves　are　close;　(3)　compared　the　peak　compressive　stress,　the　stresses　in　the　softening　curves　have　a　larger　discreteness.　©,　2015,　China　Water　Power　Press.　All　right　reserved.