Mandarin Chinese:
* Zi: "Tzu" (like "zoo" but with a "tz" sound)
* Yao: "Yow" (like the first syllable in "yowl")
Therefore, "Ziyao" in Mandarin Chinese is pronounced "Tzu-yow".
Other languages:
If you're referring to a different language, please specify so I can give you the correct pronunciation.
Let me know if you need any further help!