Majority state-owned China Mobile has more than 760 million customers but for years it has declined to provide the iPhone as the two companies argued over commercial terms.
The country's other big mobile telecommunications firms, China Unicom and China Telecom, already stock the product, and China Mobile will join them on Friday.
Analysts expect the move to boost the number of subscribers for China Mobile, which was recently awarded a government licence for 4G (fourth generation) services, and lift Apple's iPhone sales in China by millions - but in all likelihood it is far too late for the US giant to take the lead.
Apple sits in a lowly eighth place with a 3.5 per cent share as of the third quarter last year, with six Chinese companies ahead of it, many offering cheaper phones using the Android operating system.
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"The domestic high-end smartphone market is much more diversified and competitive now, leaving users more choices," said Wang Jun, an analyst for Beijing-based Analysys.
"It's likely Apple will move up one or two places in the market-share rankings, but it's impossible for it to make it into the top three or four," he said.
The iPhone launch just two weeks before the Chinese New Year, a traditional time for gift-giving, should benefit both China Mobile and Apple, analysts said.
China Mobile chairman Xi Guohua told a briefing in Beijing today that the company had received "multi-millions" of iPhone pre-orders, Dow Jones Newswires reported.
Apple chief executive officer Tim Cook told the same event: "As of this weekend, we will be selling iPhones in more than 3,000 additional locations."
"Although cooperation with China Mobile will help boost Apple's sales and market share in China, it's unlikely that its share will rise to among the top three, given the intense competition in China's smartphone market," he said.
"Smartphones that cost around USD 165 are the most popular," he added.