When　the　two-stage　compression　cycle　coupled　with　dual-cylinder　rolling　piston　compressor　is　used　in　the　room　air　conditioner　with　the　refrigerant　of　R410A,　its　heating/cooling　capacity　can　be　remarkably　improved　and　the　discharge　temperature　can　be　reduced.　By　analyzing　thermodynamically　the　two-stage　compression　heat　pump　system　coupled　with　dual-cylinder　rolling　piston　compressor,　simulated　calculation　indicated　that　the　favorable　volume　ratio　of　higher-pressure　chamber　to　lower　pressure　one　was　4/5.The　experiments　for　the　developed　prototype　were　conducted.　The　experimental　results　showed　that　the　coefficient　of　performance　(COP)　for　cooling　conditions　could　go　up　to　3.81　and　discharge　temperature　was　lower　than　91°C　when　evaporating　temperature　kept　5°C　and　condensing　temperature　varied　from　35°C　to　45°C,　and　COP　for　heating　conditions　could　rise　up　to　3.38　and　discharge　temperature　was　lower　than　111°C　when　condensing　temperature　was　40°C　and　evaporating　temperature　varied　from　-5°C　to　-10°C.　COP　could　be　improved　by　6.8%-15.4%　when　compared　with　one-stage　compression　cycle.　©　All　Rights　Reserved.