We　have　proposed　a　current　observer-based　speed　sensorless　vector　control　system　taking　into　account　both　iron　loss　and　stator　resistance　identification.　The　method　is　constructed　in　a　synchronously　rotating　reference　frame.　The　effectiveness　of　the　proposed　system　has　been　investigated　by　digital　simulation　and　experimentation.　Furthermore　important　control　parameters　such　as　stator　resistance,　observer　gain　and　filter　of　speed　estimation　are　studied　by　comparing　the　computed　result　with　experimental　one.