Wén qǐlái zhēn xiānɡ.
闻起来真香。
It smells good.
Notes:
闻起来(wénqǐlái): to smell
真(zhēn): really
香(xiānɡ): smell good
Example:
A:我带了鲜花给你。
Wǒ dàile xiānhuā ɡěi nǐ.
I bring some fresh flowers for you.
B:闻起来真香。
Wén qǐlái zhēn xiānɡ.
It smells good.