In　this　paper,　the　compressive　strength　and　failure　patterns　of　reinforced　cemented　paste　backfill　(CPB)　were　studied　aiming　to　promote　the　stability　of　backfilled　stopes.　The　concept　of　ductile　backfill　was　proposed　and　a　series　of　unconfined　compression　tests　were　carried　out　on　both　non-reinforced　and　reinforced　cemented　paste　specimens.　Portland　cement　(3%　to　5%　by　weight　of　tailings)　and　five　different　types　of　ductile　materials　(0　to　0.5%　by　weight　of　solids)　were　employed　in　this　experiment　for　the　specimen　preparation.　The　test　results　showed　that　inclusion　of　ductile　materials　enhanced　the　unconfined　compressive　strength　(UCS),　reduced　the　post　peak　stress　loss　and　transformed　the　failure　behaviour　of　specimens　from　classical　brittleness　to　ductility.　The　strength　of　CPB　reinforced　with　different　proportions　of　polypropylene　fibres　was　compared.　The　stress-strain　curves　illustrated　that　both　cement　and　fibres　contributed　to　the　increase　of　UCS,　but　higher　strain　values　at　the　peak　stress　were　achieved　by　fibre　reinforcement.　CT　sliced　images　acquired　from　X-ray　computed　tomography　(CT-scan)　demonstrated　that　the　reinforced　specimen　developed　irregular　crevices　at　the　edge　of　cross　sections　and　gained　the　capacity　of　bearing　large　displacements　owing　to　the　mobilised　tensile　strength　of　fibres.　It　leads　to　the　potential　of　avoiding　unexpected　falling　blocks　of　CPB　when　adjacent　mining　occurs.　This　finding　highlights　a　strategy　to　improve　the　self-supporting　capacity　of　the　fill　mass　with　less　cement　usage　and　reduce　the　ore　dilution　rates　when　excavating　to　adjacent　stopes.　©　2015　by　the　Canadian　Institute　of　Mining,　Metallurgy　&　Petroleum　and　ISRM.