According to Chinese news site Sina Tech said today, more than 100,000 online reservations were registered on China Unicom by 4 p.m. local time.
The iPhone 5 will be officially launched on the carrier on December 14.
The site noted that early buyers preferred the simple reservation as well as the smartphone.
Potential buyers are required to fill in their name, identity card number and phone number.
The iPhone 5 will reportedly be released in more than 50 additional countries across December.
Shipping times for the device have dropped to 2-4 business days in Australia, New Zealand and some Asian countries.