in 8th century, Buddhism in Tibet, mainly at Lhasa river valley, Yarlongzangbu river valley and Nianchu river valley, got roots and found political and financial support from local landlord and royal family; the founding of Samya monastery marked this turnpoint of Tibet history; then Tibet buddhism spred out to other parts over this plateau; after 9th century, because of then king of Lang Damo, Tibet buddhism suffered heavy damage and destroy; some lamas fed out to southern Qinghai province (Amdo) and western Sichuan province (Kham), which are relatively far from the influce of Lhasa authority; and then, this area becomes the re-birth place of Tibet buddhism;