This　paper　studies　the　influence　of　stone　dust　on　adaptability　of　polycarboxylate　superplasticizer　and　cement　by　the　experiment　of　paste　slump　and　mortar　slump　flow.　The　results　indicate　that　polycarboxylate　superplasticizer　mixed　in　mortar　increases　with　stone　dust　mixed　because　of　large　specific　surface　and　water　demand　of　stone　dust.　There　is　little　effect　on　fluidity　loss　when　the　dosage　of　stone　dust　is　below　18%,　and　it　will　increase　significantly　with　the　dosage　more　than　18%.　The　adaptability　of　polycarboxylate　superplasticizer　and　cement　will　be　bad　when　the　content　of　stone　dust　in　manufactured　sand　is　over　10%.　The　adaptability　of　polycarboxylate　superplasticizer　and　cement　can　be　evaluated　by　the　method　of　mortar　slump　flow.　©　2017　Trans　Tech　Publications,　Switzerland.