Changjiang vs Yangtze

Changjiang and Yangtze both are nouns.

Word	Noun	Adjective	Verb	Adverb
Changjiang	Yes	No	No	No
Yangtze	Yes	No	No	No

As nouns, Changjiang and Yangtze are synonyms defined as:

Changjiang and Yangtze: the longest river of Asia; flows eastward from Tibet into the East China Sea near Shanghai

Other synonyms of Changjiang include Chang, Chang Jiang, Yangtze Kiang, Yangtze River.

Changjiang (noun)	Yangtze (noun)
the longest river of Asia; flows eastward from Tibet into the East China Sea near Shanghai	the longest river of Asia; flows eastward from Tibet into the East China Sea near Shanghai