Facility　horticulture　develops　rapidly　in　China,　but　the　inside　temperature　of　plastic　greenhouse　in　winter　in　Southern　China　is　low,　which　often　makes　the　vegetable　growth　suffer　from　low　temperature　damage.　In　order　to　improve　the　thermal　environment　inside　the　plastic　greenhouse　in　winter　in　southern　China,　the　packaged　organic　phase　change　material　is　taken　as　the　research　object.,　and　two　testbeds　of　plastic　green　houses　with　shrinked　size　have　been　set　up　in　the　suburb　of　Hangzhou　city,　which　were　marked　as　the　greenhouse　with　phase　change　material　and　the　common　reference　green　house　without　phase　change　material.　The　operation　strategies　and　effects　of　phase　change　material　used　in　the　plastic　green　house　in　winter　were　studied.　A　kind　of　heat　collector　was　designed.　The　PCM　packed　in　black　bags　was　placed　in　it　during　the　day,　which　could　make　full　use　of　the　solar　energy　towas　melt　completely　and　put　in　the　greenhouse　at　night.　When　the　outdoor　air　temperature　in　the　daytime　is　between　0℃　and　8℃,　the　temperature　in　the　greenhouse　can　be　maintained　below　30℃.　The　temperature　in　the　greenhouse　can　be　significantly　increased　by　the　combined　use　of　phase　change　material　and　rubber-plastic　insulation　cotton　at　night.　The　air　temperature　in　the　greenhouse　with　phase　change　material　can　still　be　maintained　at　10.7-14.7℃,　when　the　lowest　outdoor　air　temperature　at　night　is　-4℃.　©　2020,　Solar　Energy　Periodical　Office　Co.,　Ltd.　All　right　reserved.