Arterial route in China or Taiwan (5)
I believe the answer is:
aorta
'arterial route' is the definition.
(the aorta is an artery)
'in china or taiwan' is the wordplay.
'in' indicates the answer is hidden within the clue.
'AORTA' is hidden within 'china or taiwan'.
(Other definitions for aorta that I've seen before include "Major artery of the body" , "Vital blood vessel" , "Large artery of the heart" , "Main artery of body" , "Principal artery" .)