At present, there are only 250 Vietnamese golden monkeys left, which is the only golden monkey in the world outside China. Vietnamese golden monkey, also known as Tokyo golden monkey, is small, with black chest and abdomen and light yellow inside limbs; It is only distributed in the low-altitude subtropical rain forest in the limestone mountains between Xuanguang Province and North Pacific Province in northern Vietnam. At present, there are only four species of golden monkeys in the world. According to scientists' speculation, the number of Vietnamese golden monkeys is about 250. Compared with China, which has 20,000 Sichuan golden monkeys, 750 Guizhou golden monkeys and 2,000 Yunnan golden monkeys, there are 250 Vietnamese golden monkeys. 1997, IUCN listed it in the red list of critically endangered species.
Vietnamese golden monkey was discovered in 19 10; In the following decades, there was no news about this species, and people could only see the type specimens collected by the British Museum of Natural History. At 1989, they were discovered again; In 2002, the British International Organization for the Protection of Animals and Plants (FFI) began to protect the Vietnamese golden monkeys in northern Vietnam, investigated their population numbers and the factors to contain their threats, and achieved remarkable results, and discovered new population distribution one after another. In April 2008, Vietnamese villagers reported seeing this kind of monkey on the Sino-Vietnamese border in Hejiang Province, and FFI sent a team to explore it. At that time, the investigation team found a total of 15 -20 golden monkeys, including 3 cubs.