User　profiling　is　essential　for　understanding　the　characteristics　of　various　users,　contributing　to　understanding　their　requirements　better.　User　reviews　by　nature　are　invaluable　sources　for　acquiring　user　requirements　and　have　drawn　increasing　attention　from　both　academia　and　industry,　which　have　not　been　well　explored　by　traditional　user　profiling　techniques.　This　paper　carries　out　a　systematic　mapping　study　on　review-based　user　profiling.　Specifically,　21　out　of　1372　papers　were　carefully　selected　for　investigation　under　a　standardized　and　systematic　procedure.　By　carrying　out　in-depth　analysis　over　such　papers,　we　have　identified　a　general　process　that　should　be　followed　to　perform　review-based　user　profiling.　In　addition,　we　perform　multidimensional　analysis　on　each　step　of　the　process　to　review　current　research　progress,　identify　challenges,　and　propose　potential　research　directions.　The　results　show　that　although　traditional　methods　have　been　continuously　improved,　they　are　not　effective　enough　to　unleash　the　full　potential　of　large-scale　user　reviews,　especially　the　use　of　heterogeneous　data　for　multi-dimensional　user　profiling.