To　study　the　insulating　performance　of　the　thin　thermal　insulating　material.　A　testing　system　has　been　developed　with　LabVIEW　for　measurements　of　thermal　conductivity　on　building　thermally　insulating　materials.　The　thermally　insulating　coating＇s　thermal　conductivity　measuring　system　based　on　virtual　instrument　was　discussed.　This　instrument　has　the　ability　of　on-line　analysis　and　evaluating　materials＇　thermally　conductivity.　And　it　can　be　controlled　by　mcu　89c2051　one　wire　temperature　sensor　ds18b20　and　so　on.　It　gives　the　designed　method　and　controlled　flowchart　of　testing　the　thermal　conductivity　by　LabVIEW.