Due　to　the　small　size　and　no　battery　needed,　passive　radio　frequency　identification(RFID)　tag　is　easily　integrated　to　everything.　It　is　useful　on　item-level　location　scenarios　like　finding　an　important　document　at　home.　Received　signal　strength　indicator(RSSI)　based　fingerprint　indoor　positioning　methodology　is　not　only　appropriate　for　the　active　short　range　radio　frequency(RF)　system,　but　also　suitable　for　passive　RFID　system.　According　to　our　repeated　experiments,　we　find　out　that　although　a　tag＇s　received　signal　strength(RSS)　values　distribution　against　a　fixed　position　doesn＇t　conform　to　Gaussian　process,　the　value　probability　distributions　is　always　similar　in　the　nearby　positions.　A　fingerprint-like　solution　by　using　RSS　value　probability　distribution　comparison　for　passive　RFID　system　is　presented　in　this　paper.　The　first　phase　is　to　build　a　probability　distribution　fingerprint　database　for　the　targeted　area,　while　the　second　phase　is　the　real-time　probability　comparison　and　location　determination.　Based　on　our　experimental　result,　the　new　solution　using　our　probability　distribution　comparison　method　performs　higher　positioning　accuracy　than　the　existing　approach.