Possibly there is a trace of ancestor worship even here; but the two usages have diverged.
Like their neighbours the Cambodians and the Chinese, the Annamese have a great respect for the dead, and ancestor worship constitutes the national religion.
All theories of religion which give prominence to ancestor worship and the cult of the dead are to a certain extent Euhemeristic. But as the sole explanation of the origin of the idea of gods it is not accepted by students of comparative religion.
The Euhemerist theory mainly appeals to ancestor worship - a fact of undoubted importance in the history of religion, especially in China and in ancient Rome.