A　newly　designed　vapor-injected　heat　pump　using　injection　subcooling　was　adopted　to　improve　the　heating　performance　of　a　R32　heat　pump　at　cold　regions.　A　composite　test　system　was　used　to　research　the　system　working　performance.　Three　kinds　of　system:　single　stage　system　(SS　system),　vapor　injection　system　(VI　system),　vapor　injection　with　subcooling　system　(VIS　system)　were　tested　and　heating　performance　was　compared　with　each　other.　The　results　showed　that,　vapor　injection　with　subcooling　can　further　decrease　the　R32　compression　discharge　temperature　and　made　the　system　run　under　evaporating　temperature　lower　to　-20　?;　The　VI　cycle　shows　the　highest　heating　capacity　and　heating　COP　among　all　the　cycle　options,　but　the　SS　cycle　shows　the　lowest　values.　©　ACRA　2018　-　9th　Asian　Conference　on　Refrigeration　and　Air-Conditioning.　All　rights　reserved.