Wǒ bù chōuyān.
我不抽烟。
I don't smoke.
Notes:
我(wǒ): I
不(bù): not
抽烟(chōuyān): to smoke
Example:
A:你抽烟吗?
Nǐ chōuyān mɑ?
Do you smoke?
B:我不抽烟。
Wǒ bù chōuyān.
I don't smoke.