Bird's Nest refers to the nest built by the saliva secreted by some Swifts of Swift Family of Swift Order and several Jin Siyan species of Swift genus, and then mixed with other substances. Also known as Swallow Vegetable, Swallow Root and Swallow Vegetable, bird's nest can be divided into "House Swallow" and "Cave Swallow" according to the nesting place. Cave Swallow has different colors due to the influence of minerals, including Bai Yan, Yellow Swallow and Red Swallow, while House Swallow has only one color of ivory. The so-called "blood swallows" on the market are said to be made by artificially cultured house swallows through "bird droppings".

The main producing areas of bird's nest are from the Philippines in the east to the caves of desert islands near the coast of Myanmar in the west, with Indonesia, Malaysia, Sandakan, Singapore and Thailand and the South China Sea islands in the majority. Among them, Indonesia has the best bird's nest quality and the largest bird's nest production, followed by Malaysia, because the weather and environment are most suitable for swallows to live together.

According to statistics, by the end of 20 10, Indonesia's bird's nest accounted for 85%-90% of the global bird's nest production, Malaysia accounted for 5%- 10%, Thailand 3%, Vietnam, the Philippines and other places about 2% (refer to the data of Hong Kong Trade Department for several years). A subspecies of Jin Siyan in Java, namely cfuciphagemmani, was once collected on Yannan Island, which can produce edible bird's nest.

Jin Siyan, with a short mouth, is produced in the southwest of China and the southeast of Xikun. The earliest works with detailed records are Materia Medica and Ben Jing Feng Yuan. There are six species of bird's nest in Jin Siyan that can produce bird's nest. The saliva secreted by various birds of Swift (Apodidae) and its down are mixed and condensed on cliffs or farmhouses.