Vapor　compression　heat　pump　is　of　great　significance　to　space　thermal　control.　It　can　effectively　regulate　the　temperature　of　electronic　devices　to　ensure　proper　operation.　Weightlessness　is　a　significant　factor　affecting　the　operation.　Weightlessness　test　of　vapor　compression　heat　pump　was　conducted　to　investigate　the　weightless　effect　on　its　performance.　Weightlessness　test　was　achieved　by　free　fall　on　a　platform　60m　above　the　ground.　The　tests　of　continuous　weightlessness　and　single　stroke　of　weightlessness　were　presented　and　analyzed.　The　results　showed　that　the　weightlessness　decreased　the　evaporative　heat　transfer　performance　and　enhanced　the　condensation　heat　transfer　performance.　It　is　then　advisable　to　increase　heat　transfer　area　of　the　evaporator　in　the　design　of　future　vapor　compression　heat　pumps,　and　the　design　of　condensers　could　still　be　based　on　the　routine　method　adopted　in　ground　applications.　This　part　of　experimental　data　for　space　application　of　vapor　compression　heat　pump　is　expected　to　be　of　great　significance.