Hopea hongayensis belongs to Hopea genus, Dipterocarpaceae family, was found in Quang Ninh province (Vietnam) by Tardieu Marie Laure (1902-1998), a French botanist and then named as Hopea hongayensis Tardieu. This is a valuable species for sciences (endemic species), for economic (fine wood) and for medicine (use as medical). However, this species is currently facing an extremely high risk of extinction because of over-exploitation and habitat decline. Globally, Hopea hongayensis was listed as CR, A1cd +2cd, C1, D under IUCN 2012 criteria. At present, there is no thoughtful research on this species in Vietnam. Chloroplast MatK gene is determined to be useful for studies on classification and barcoding. In this study, Hopea hongayensis's chloroplast MatK gene was sequenced for addition the genetic database of rare plant of Vietnam and analysis of genetic relationship between Hopea hongayensis with other dipterocarps species in the world.