An employee uses an Apple iPhone to demonstrate to reporters how to pay using the Apple Pay service at an Apple store in Beijing, Feb 17, 2016. [Photo/Agencies]

Apple Inc remains the most popular smartphone brand in China, despite its recent poor performance in its second-largest market, a new report said.

The report, released by China Mobile Communications Corp, is based on the analysis of the world's largest telecom operator's roughly 800 million subscribers. This is the first time that China Mobile opened its big data report to public.

In May, about 15 percent of China Mobile's subscribers are using iPhones, which amounts to about 120 million users. Domestic brands Xiaomi Corp and Huawei Technologies Co Ltd rank alongside Samsung Electronics Co as the second-most popular brands, with each company accounting for 9 percent of subscribers.

When it comes to the fastest-growing handset makers, smaller local rival vivo Mobile Communication Technology Co Ltd prevailed thanks to its sprawling offline-retail channels in small cities. About 14 percent of China Mobile subscribers registered in the first five months of this year are using vivo's handsets.

James Yan, research director at Counterpoint Technology Market Research, said Apple's strong performance in this report is not a contradiction of its recent declining smartphone sales in China.

Top smartphone brands among China Mobile users

"Compared with the iPhone 6 series, which was a record-breaking hit, the iPhone 6S was far less popular, so its sales as a whole declined," Yan said. "But compared with some local players, the iPhone 6S still delivers a relatively good performance."

According to Yan, the iPhone 6S had a strong start in the first several months of this year, but the demand quickly died out once the replacement cycle was finished, given that iPhone 6S only has incremental improvements to iPhone 6.

Still, Apple is the brand with the highest consumer loyalty in China. Forty-five percent of Apple users choose to buy another iPhone when they replace their old handsets, far higher than the average of 18 percent among other brands.