Pham Van Hiep, 26, of the north-central Nghe An Province, was caught with the whole skin of a tiger and 5.4 kilos of bones as he was trying to cross the border in Quang Ninh Province.
He has been handed over to the local police for questioning.
Tiger bones are used in Vietnam and China to make traditional medicine to treat bone- and joint-related ailments. The bones are boiled until they become glue-like, and then dried and sold for around VND20 million ($860) per 100 grams.
Besides bones, the animal is also trafficked for its meat, skin and claws.
Local conservation group Education for Nature-Vietnam estimates that between 2006 and September 2016 it investigated 971 cases of trading, transporting, selling and advertising of tigers or tiger products.
Violation of conservation laws in the case of endangered animals is punishable by up to seven years in jail in Vietnam.