The extremist group posted pictures of the two men wearing yellow prison outfits in the latest issue of its online magazine Dabiq, which was released Wednesday.
It identifies the Norwegian man as Ole Johan Grimsgaard-Ofstad, 48, from Oslo. It identifies the Chinese man as Fan Jinghui, 50, a freelance consultant from Beijing.
The magazine lists a telegram number for "whoever would like to pay the ransom for his release and transfer."
It does not say when or where the two were captured. The IS group controls large parts of Iraq and Syria. It has killed several captives in gruesome videos released online.