Kundian wood is a heavy (hard) Polei wood of the genus Hopea spp. of Borneolum family. It is commercially known as Giam and distributed in Malay Peninsula, Kalimantan Island, Philippines and India in Southeast Asia. Most of them are small to medium-sized trees, rare large trees. About 24 species. Hopea nutens, with a height of 18-30 m and a diameter of about 130 cm, are distributed in Malay Peninsula and Kalimantan Island. It is difficult to distinguish the color of heartwood: the heartwood is yellow, green when fresh, and yellow or dark reddish-brown when long; the sapwood is yellow, about 1 cm thick, and the fresh surface is exposed to the atmosphere for a long time, but the color of the heartwood does not change significantly. The growth ring was not obvious. Pipe holes are visible under the naked eye, slightly smaller and larger (quite consistent); there are abundant infiltrates in the catheter. Wood has luster, no special smell and taste. The texture is deeply interlaced; the structure is uniform. Dry shrinkage to medium; good dimensional stability of wood. Wood weight is very heavy and hard; air-dry density is 0.87-1.22g/cm3. The strength is very high. Wood is very rotten. Wood naturally dries very slowly. Sawing, drilling and turning are difficult.
Wood has high strength and durability, so heartwood does not need to be preserved. Suitable for shipbuilding, especially for making wooden boats (such as keel), large yachts, bridges, poles, sleepers, carriages, truck frames, etc. It can also be used for beer, wine barrel, butter mixing barrel, etc. These timbers are old boat wood with many big nails on the old boat wood. It is not easy to dismantle the nails from the old boat wood.
Pontianak, located just below the equator, is the confluence of the Kapuas and Landak rivers in West Kalimantan, Indonesia. The city was founded by Arab pirates and businessman Abdul Rahman in 1770. Later, with the discovery of gold deposits a few kilometers north of this area, Kundian developed rapidly and became a concentration area for overseas Chinese. It is said that in the past, Guangdong imported more of this kind of wood from Kundian, so people call it Kundian wood.
Because of its fine structure, hard material, strong toughness, corrosion resistance, strong moth resistance, and not afraid of dampness, placed in the wet place will not corrode, and the more solid it is immersed in the water, it is used for keel inside and outside the ship. In the Qing Dynasty, Guangzhou shipbuilding industry mostly used Kundian wood. At that time, Guangzhou shipbuilding industry was located in the southern bank of the Pearl River in Guangzhou, where Kundian wood furniture workshop was also concentrated, while sour branch flower pear furniture workshop was concentrated in the vicinity of Yudaihao (moat) between the inner city and outer city of Guangzhou, so there was a distinction between Huali and Kundian furniture industry in Guangdong, and the workshops and groups of both were distinct. 

There are also Kundian wood used as building materials. For example, the Mao's ancestral temple, a large ancestral complex in Lianxi Village, Huangge Town, Nansha District, Guangzhou, ranks third among the four famous ancestral temples in Guangzhou. The beams and pillars of the ancestral temple are particularly tall and sturdy, with diameters ranging from 30 to 60 cm. These timbers are Kundian wood, which is said to have been transported from Myanmar in the same year. They have not been eaten by termites for hundreds of years and have not been preserved to date. Kundian wood is a well-known high-strength structural material with yellow-brown to brown color, fine and uniform structure and oblique texture. It has the advantages of hard wood, good brightness after painting, and lower price than acid branches. In the furniture of Guangzhou writers, the wealthy middle and upper families use acid branches and rosewood, while the middle and lower families use Kundian wood. Generally, chairs, benches, beds, couches and other furniture can be made of Kundian wood. Kundianmu occupies an important position in the furniture of Guangzhou writers because of its ancient color and heavy shape.