Sorry, I know nothing about politics in China.

All I can say is that in some countries (mine, for instance) "
Premier" is the "
Prime Minister" (the head of the government), while "
President" is the person with the highest political position. It is somewhat similar to what happens in the UK, where they have a prime minister (now, Gordon Brown) and a queen (now, Elizabeth II) instead of a president -- well, that's obvious, since the UK is not a republic.
In some other countries, the president is also head of the government, and as such he's also premier (if I'm not mistaken, this happens in France).
Do you know how it works in China? This should help!