If I call China use FaceTime over the WiFi, is it free?
Be aware that iOS 6 supports facetime over 3G networks. So take a look on your system preferences for facetime. In that case, i would switch off "Facetime over cellular". may you outside of your Wifi range while talking ...
It will be free for you. If the person you will call is connected to the internet by carrier instead of connected with Wifi connection, He/she will be billed by He/she carrier
Only for normal data charges, though. There is no separate fee for using FaceTime, from Apple or the carrier.
Retrieving data ...