About " China's " and "Chinese"
I don't know how to use " China's " or "Chinese".Please see two sentence:
Nokia responded by promoting its Nokia 7650 handset that can also be used as digital camera,with a bigger Chinese market share in mind.
The proportion of China's aged population is largest in Shanghai.

Question

About " China's " and "Chinese"
I don't know how to use " China's " or "Chinese".Please see two sentence:
Nokia responded by promoting its Nokia  7650 handset that can also be used as digital camera,with a bigger Chinese market share in mind.
The proportion of China's aged population is largest in Shanghai.

Answer

China is referring to country. Chinese refers to the people in china. Just like Singapore and Singaporean.

Answer

China is a noun while Chinese is an adjective.  That's why they say the 'Chinese market'  The word China describes or say what type of market they are talking about.  Other examples could be:  The 'American (adjective) company, Wallmart.' But  - 'America ( noun) is a big country. '  'Jamaica  (noun) has excellent athletes' but - 'Jamaican ( adjective) athletes are excellent.'  

I hope you find my explanation helpful.