From Apple's press release:
Apple today announced that the App Store has added UnionPay as a payment option for customers in China. China UnionPay is the most popular payment card in China and will provide App Store customers with a simple and more convenient way to purchase their favorite apps. Customers can easily link their Apple ID with a UnionPay debit or credit card for one-tap purchases.
“The ability to buy apps and make purchases using UnionPay cards has been one of the most requested features from our customers in China,” said Eddy Cue, Apple’s senior vice president of Internet Software and Services. “China is already our second largest market for app downloads, and now we’re providing users with an incredibly convenient way to purchase their favorite apps with just one-tap.”
Full release at the link.