If it is unlocked and uses the same protocol (GSM or CDMA) and
frequencies as the Russian carrier you intend to use.
Warranty is not international - iPhone will have to be returned
to China for service or replacement. Buy one locally from an
authorized source to avoid future problems.
Unless you live in China, you don't want to purchase an iPhone there, whether officially unlocked or not. Certain iPhone features are restricted, by law, on all iPhones sold in China. You've been warned.
VERY probable not, since WiFi channels are different and not overlapping (La Pastenague, thanks) and porbably the 3G does not work either. And the waranty is also an issue.
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