Last name How Long (How Long 
, ถียัง 
) , around the world, is a very rare surname. The surname How Long is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Very seldom, How Long is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| How Long | Malaysia |
| ถียัง | Thailand |