In　this　paper,　the　two　solar　greenhouses　with　the　same　sizes　of　a　vegetable　planting　base　located　in　Beijing　were　researched,　and　one　was　taken　as　test　greenhouse,　the　other　reference　greenhouse.　The　phase　change　materials　(PCMs)　was　applied　on　the　inner　surface　of　the　test　greenhouse＇s　north　wall　in　order　to　enhance　the　wall＇s　ability　to　collect　and　store　solar　energy　and　increase　the　utilization　rate　of　solar　energy,　and　then　improve　the　indoor　thermal　environment　of　the　greenhouse.　According　to　the　measured　data　from　Dec.　21,　2010　to　Jan.　18,　2011,　the　results　showed　that　the　thermal　performance　of　the　test　greenhouse　with　40　mm　thickness　PCMs　was　better　than　that　of　the　reference　greenhouse　with　conventional　brick　materials.　During　the　opening　of　the　heat　preservation　quilt　in　the　daytime,　the　inner　surface　average　temperature　of　the　north　wall　of　the　test　greenhouse　was　about　1-2.7°C　higher　than　that　of　the　reference　greenhouse,　the　soil　average　temperature　of　the　plow　layer　and　the　average　indoor　ambient　temperature　of　the　test　greenhouse　were　about　0.5°C　and　0.2-2.1°C　higher　than　that　of　the　reference　greenhouse,　respectively.　During　the　closing　of　the　heat　preservation　quilt　at　night,　the　inner　surface　average　temperature　of　the　north　wall,　the　soil　average　temperature　of　the　plow　layer　and　the　average　indoor　ambient　temperature　of　the　test　greenhouse　were　about　2.1-4.3°C,　0.5-1.4°C　and　1.6-2.1°C　higher　than　that　of　the　reference　greenhouse,　respectively.　So　the　PCMs　can　improve　the　thermal　environment　for　crop　growth　and　increase　the　utilization　rate　of　solar　energy　in　solar　greenhouse.