Abstract
The Catba national park (20$\circ$42'-20$\circ$54'N, 106$\circ$54'-107$\circ$09'E), which is a representative protected area in northeast Vietnam, was first investigated in terms of phytosociology of the Zurich-Montpellier School. 15 plant communities were identified from the seven vegetation types: Teetaria-Amoora gigantea community, Blechmum-Pitecellobium ferrugineum community, Impatiens-Dracaena cambodiana community, Rhizophora apiculata community, Avicenia marina community, Panicum repens community, Heterosmilax-Zanthoxylum nitidum community, Stachytarphyta jamaiensis-Bidens bipinnata community, microstegium vagans community, Dicranopteris linearis community, Randina-Sapium sebiferum community, Psidium gujava community, Elephantopus scaber community, and chirita aratformis community. Traditional pasturing and shifting agrie\culture by indigenous people in Catba national park were recognized as main disturbance regies, which have been far above sustainable levels. Ecological strategies for conservation and sustainable use on national park' ecosystem were proposed: (1) development of awareness program on sustainable life style of indigenous people, (2) establishment of multiple use module system of national park, (3) ecosystem monitoring of permanent ecological sites.