Vapor　compression　heat　pump　has　good　prospects　in　future　large-scale　spacecraft　thermal　control　technology.　Compressor　is　a　key　component　in　vapor　compression　heat　pump.　It　is　essential　to　study　its　adaptability　under　micro-gravity.　In　this　paper,　an　experimental　system　was　built　up　to　test　the　performance　of　inverted　compressor　subjected　to　micro-gravity.　The　performance　of　compressor　upright　and　inverted　was　compared.　The　influence　of　compressor　speed　on　the　performance　of　vapor　compression　heat　pump　was　investigated.　The　results　showed　that　the　inverted　compressor　could　be　considered　gravity-independent　because　of　normal　operation.　Compressor　discharge　temperature　and　power　increased　with　compressor　speed.　However,　the　COP(Coefficient　of　Performance)　was　less　than　that　of　compressor　upright.　The　maximum　COP　obtained　with　upright　and　inverted　compressor　were　8.4　and　7.6,　respectively.　The　experiment　subject　to　micro-gravity　of　vapor　compressor　heat　pump　provides　an　experimental　basis　and　lays　foundation　for　future　space　applications.　©　2016　IEEE.