As　the　tensile　strength　of　concrete　is　lower,Cracking　is　perhaps　the　well　known　and　most　common　distress　in　concrete,such　as　cracks　due　to　shrinkage　and　temperature.　These　cracks　will　cause　serious　problems　when　cracked　reinforced　concrete　structure　is　subjected　to　corrosive　agents.　For　example,　the　seepage　of　salty　solutions　through　cracks　to　the　reinforcing　steel　may　lead　to　corrosion　of　the　steel　bar　and　ultimately　failure　of　the　structure.　But　when　polymer　latex　is　mixed　into　concrete,the　concrete　property　is　modified　obviously.　This　type　of　concrete　products　has　excellent　mechanical　strength　and　durability　properties,　markedly　high　erosion,　abrasion,　cracking,　impact　and　freeze-thaw　resistance.　The　polymer　in　concrete　can　minimize　cracking　and　control　the　crack　width.　In　addition,it　has　the　excellent　bonding　capacity　to　reinforced　bar　and　old　structural　surface.　Combining　the　application　of　polymer　cement　concrete　in　some　engineering,　this　paper　analyses　and　research　the　modifying　mechanics　of　polymer　cement　concrete.　In　last,　the　future　development　and　the　application　of　PCC　in　the　strengthening　and　repair　of　bridge　and　road　engineering　is　foreseen.