In this paper,a strong allelopathic rice variety PI312777 and a weak allelopathic rice variety Lemont were used as test materials,and the root exudates of two rice varieties grown in the media of sand and soil were respectively collected by using circulation system approach.The terpenoids in ether-extracts were detected by GC-MS,and characterized by spectrum database.The results showed that some terpenoids such as limonene oxide,limonene dioxide,carvone oxide,carveol,and cedrol were detected in the ether-ex...