Aquilaria tree is a species under the Thymelaeaceae family. In Peninsular Malaysia, there are five (5) species that were identified namely: Aquilaria malaccensis, Aquilaria microcarpa, Aquilaria hirta, Aquilaria beccariana and Aquilaria rostrata. Aquilaria trees can naturally produce agarwood from the response of the tree to fungi infection, injury and pest attack. This tree will produce a kind of oil with a distinctive smell to protect the injured parts such as the stems, branches and roots. The oil will eventually harden and is known as resin. Agarwood can be categorized into various grades. In the Forestry Department of Peninsular Malaysia, the grade of agarwood is determined based on their characteristics such as color, size/shape, odor and thickness. This grade is used for the purpose of tax collection before the product is sold.