For　a　space　heating　ASHP　unit,　frosting　on　its　outdoor　coil　would　adversely　impact　its　normal　operation,　requiring　frequent　defrosting　and　resulting　in　low　operating　efficiency　and　poor　indoor　thermal　comfort.　It　has　been　shown　that　varying　the　speeds　of　both　compressor　and　outdoor　air　fan　in　a　variable　speed　(VS)　ASHP　unit　can　lead　to　different　outdoor　coil　surface　temperatures　and　thus　different　frosting　suppression　performances.　However,　this　can　also　result　in　different　output　heating　capacities　from　the　ASHP　unit.　To　establish　the　comprehensive　relationship　between　frosting　suppression　performances　and　the　total　output　heating　capacity　for　a　VS　ASHP　unit,　an　experimental　study　on　developing　the　condensing-frosting　performance　maps　for　a　VS　experimental　ASHP　unit　under　different　speed　combinations　of　its　compressor　and　outdoor　air　fan　at　three　Test　Conditions,　was　carried　out　and　the　study　results　are　presented　in　this　paper.　The　obtained　performance　maps　clearly　demonstrated　that　for　the　experimental　ASHP　unit,　varying　the　speeds　of　its　compressor　and　outdoor　air　fan　would　result　in　not　only　different　outdoor　coil　surface　temperatures,　but　also　different　total　output　heating　capacities.　A　higher　outdoor　coil　surface　temperature　and　thus　a　better　frosting　suppression　performance　may　be　achieved,　but　usually　at　the　expenses　of　losing　some　of　its　total　output　heating　capacity.　On　the　other　hand,　the　experimental　results　also　suggested　that　when　the　experimental　ASHP　unit　was　operated　at　different　speed　combinations　that　can　lead　to　the　same　or　similar　total　output　heating　capacities,　its　operating　characteristics　in　terms　of　outdoor　coil　surface　states　and　the　total　output　heating　capacity　can　be　remarkably　different.　The　obtained　condensing-frosting　performance　maps　may　be　used　as　the　guidance　for　the　design,　operation　and　control　of　ASHPs　for　frost-free　operation.