As　we　all　know　that,　SLAM　(Simultaneous　Localization　and　Mapping)　are　vital　for　mobile　robot.　This　paper　presents　a　method　of　map　building　using　interactive　GUI　(Graphical　User　Interface)　for　an　indoor　service　mobile　robot　because　of　the　uncertainty　of　the　sensors.　What＇s　more,　the　operator　can　modify　the　map　compared　with　the　real-time　video　from　the　web　camera　of　the　mobile　robot.　In　the　proposed　system,　EKF　(Extended　Kalman　Filter)　was　used　to　improve　the　precision　of　self-localization　of　the　mobile　robot.　This　paper　also　introduces　the　architecture　of　the　proposed　system　and　gives　some　experimental　results.　©　2010　IEEE.