The　main　problem　to　use　solar　energy　resources　for　winter　fresh　air　heating　is　how　ensure　the　supply　air　temperature　stable　under　unstable　solar　radiation.　So　the　solar　energy-phase　change　thermal　storage-fresh　air　heating　system　is　built　to　afford　fresh　air　load　in　official　building.　In　order　to　stabilize　supply　air　temperature,　operating　strategy　and　operating　conditions　research　based　on　charge/discharge　characteristic　of　latent　thermal　storage　and　auto　control　technology　is　carried　out　in　a　sunny　day　in　winter　in　Beijing.　Experimental　results　indicate　that　the　operating　strategy　is　feasible.　System　supply　air　temperature　can　be　controlled　at　27.5~28.5°C.　The　operating　strategy　can　also　be　used　in　other　weather　conditions.