Abstract: Permian basic volcanic rocks are located in the Eastern Mountains of Selong,Nyalam County,on the northern slope of the Himalayas,southern Tibet.Volcanic rocks of both the Jilong Formation and the Selong Group show major element ,trace element and REE geochemical characteristics of the volcanic series occurring in the continental extensional-rift environments.Therefore,the natures and eruptive tec-tonic environments of the two suites of volcanic rocks are the same.The Permian continental extensional-rift volcanism in the area marked the beginning of break-up of the supercontinent Gondwana.