As　we　all　know　that,　it　is　vital　to　process　environment　data　in　map　building　of　mobile　robot.　This　paper　presented　two　algorithms　of　map　building　using　LRF　for　an　indoor　service　mobile　robot.　Then　we　find　their　advantages　and　disadvantages,　and　the　scope　of　application　by　comparing　them　in　model　and　experiment　in　order　to　utilize　effectively　in　practice.　Experiments　in　indoor　environment　prove　that　the　algorithms　can　meet　the　demand　of　map　building　in　environment　with　different　complexity.　Hence,　we　can　select　appropriate　map　building　algorithm　for　different　practical　environment　where　mobile　robot　moves.　This　paper　also　introduces　the　architecture　of　the　proposed　system　and　gives　some　experimental　results.　©2010　IEEE.