Tim Cook, Apple's chief executive, said in April that the company planned to double the number of Apple stores in China - it has 11 - over the next two years. "We still see a significant opportunity in China," Mr Cook told analysts.
Analysts say Samsung is somewhat better positioned than Apple to take advantage of the expected surge in sales of cheaper smartphones because it already sells a broader range of handsets in China.
Samsung declined to discuss its strategy for China, saying only that it planned to introduce "various products that meet consumer needs in the future."
What happens in China is also important because success there could help smaller companies develop the strength to move into emerging markets around the globe. While most smartphones are made in China, Chinese handset makers have so far struggled to export phones under their own brand names.
"The fear for Apple and Samsung is that if they don't maintain a strong position in China, other players, mostly Chinese players, will do that instead, and then use that as a springboard to attack them in other markets," said Ian Fogg, an analyst at IHS.
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