The Taiwan blue magpie is endemic to Taiwan. It lives in broadleaf forests at elevations of 300–1,200 m.
It is 63–68 cm in length. The tail measures around 34–42 cm in length, and the wings are 20 cm long. It weighs 254–260 g. The plumages of the male and female are similar. The head, neck and breast are black. The eyes are yellow, and the bill and feet are red. The rest of the plumage is mostly blue. The wings and tail feathers have white tips. The underwing-coverts are dark grey, and the flight feathers are light grey. The uppertail-coverts have black tips. The central pair of tail feathers are the longest. The other tail feathers have black bands. Chicks are greyish, with a short tail and greyish-blue eyes.