The　test　rig　was　established　on　the　basis　of　exploiting　foil　air　bearings　to　test　the　static　and　dynamic　performances　of　new　compliant　aerodynamic　foil　air　bearings.　The　experiments　were　performed　to　identify　the　lift　off　speed　and　load　capacity　of　foil　journal　air　bearings.　The　lift　off　speed　of　foil　journal　air　bearing　was　analyzed　through　two　methods:　friction　torque　between　the　surface　of　rotor　and　bearing,　and　the　spectrum　of　radial　displacement　response.　The　results　of　experiments　shows　that　the　friction　torque　reduces　and　reaches　a　steady　value　gradually　after　lift　off　because　of　rub-impact　minishing.　The　spectrum　figure　is　regular　and　there　only　appears　larger　components　of　low　multiple　working　frequencies.　The　components　of　high　multiple　working　frequencies　and　other　frequencies　are　very　small.　The　lift　off　speed　of　foil　journal　air　bearing　obtained　from　these　two　methods　is　basically　consistent.　In　terms　of　load　capacity,　the　eccentricity　between　the　center　of　rotor　and　air　bearing　increases　as　the　load　acting　on　bearing　increases.　Under　the　same　load,　the　eccentricity　during　offloading　is　larger　than　that　of　loading　because　there　is　energy　loss　during　offloading　due　to　foil　elastic　deformation.