Apple has begun storing personal data for some Chinese users on servers provided by China Telecom, marking the first time that the company has stored user data on mainland Chinese soil.
Apple attributed the move to an effort to improve the speed and reliability of its service.
It also represents a departure from the policies of some technology companies, notably Google, which has long refused to build data centres in China due to censorship and privacy concerns.
All data stored with China Telecom, as with all data centre providers worldwide, will be encrypted, Apple said in a statement.
"Apple takes user security and privacy very seriously," it said.
"We have added China Telecom to our list of data centre providers to increase bandwidth and improve performance for our customers in mainland china. All data stored with our providers is encrypted. China Telecom does not have access to the content," the company added.
Technology companies seek to position data centres as close to their customers as possible because smaller physical distances mean faster service speeds.