Dipterocarpus costatus belongs to family Dipterocarpaceae and is locally known as keruing bukit. It is a large deciduous tree and grows to height of 25 to 40 m. This species is widely distributed in the Andaman Islands, Bangladesh, Myanmar, Thailand, Indo-China, Laos and Peninsular Malaysia.
Bukit meaning hill refers to the most preferred habitat of the species. It occurs at the lowland to hill forests at altitudes of 600 to 1100 m. In the seasonal forests of the northern states in the peninsula, it occurs almost at sea level. D. costatus is a gregarious tree and sometimes dominates the upper canopy.
This species has a large straight bole, and its bark is usually greenish grey with yellowish brown patches where scales had recently fallen. When the bark is cut, it reveals a purple-red layer below the outer bark. The outer surfaces of mature stipules are covered with golden silky hairs and the stipules may reach to 5 cm long. It has a small sub-ovate or ovate-lanceolate leaf with about 13 nerved, size about 10 x 7 cm and tomentose on the undersurface. The fruits has calyx tube about 2 cm long, sharply angled, sparsely furnished with golden stellate hairs and wings size to about 11 x 2.5 cm.
The timber is used for general construction and in ship building, but it is not durable in the open. Its resin is valuable in the paint industry. In Cambodia, the resin is used particularly for caulking of boats and making torches.
Dipterocarpus costatus is considered Vulnerable (VU A4c) in Malaysia. This species is threatened by logging activities and loss of habitats. Even though it is given a low threatened category, the populations of D. costatus still requires regular monitoring in order to protect this species from extinction in the future.