Cognomen Iuan (Йуан 
, Iuan 
, Юан 
) , throughout the world, is quite a rare surname. The last name Iuan is habitual in Taiwan, where it is a rare surname, Kyrgyzstan, and Malaysia. Not in comparison with a country's population, it is the most numerous in Russia, Malaysia, and Taiwan. Also, Iuan is the forename as well as the last name.