Together with the largest likely from old models, iPhone 6s Plus and the otterbox iPhone 6s face challenges, despite Chinese customers' insatiable hunger for the new Apple smartphone models.
A research note shows the previous models, otterbox iPhone 6 and iPhone 6 Plus, experienced leading sales ahead of the new handsets were released in September, that might encroach the market growth of new models, Xinhua news agency reported.
Both previous recent models were the best selling smartphones in China from June till August, according to a report - Kantar Worldpanel based market research firm.
"Buyers mentioned clarity and resolution, camera quality and display size as the three most important purchase drivers," said Tamsin Timpson, strategic penetration manager of the organization 's Asia division.
In the three-month circle, smartphone sales represented 84 percent of complete phone sales in China.
The report is a familiar phenomenon that some Chinese consumers, especially iPhone buyers, are inclined to select the older version with favourable prices ahead of new product release, although it failed to show what's behind the favour for the last models.
To date, the new models have performed well in the Chinese market, the world's second biggest after the US.
Apple sold around three million otterbox iPhone 6s and iPhone 6s Plus in the week following the launch, according to media reports.
In America, however, market share for Apple iOS between August and June was at its lowest point since August 2014, as customers waited for the new products to eventually become available in September, the report revealed.