Can I buy a sim card for my sony ericsson w810i phone in China?

I have a sony ericsson w810i phone that I got here in the US and I am going to china soon. I already have a code to unlock my phone from my provider and I wans wondering if it was possible for me to get a sim card for my phone in Shanghai to use in Nanjing.

Yes you can...I did exactly the same...I unlocked my Sony Ericsson W810i from Mobileunlocksolutions.com and removed the network lock after which I was able to swap simcards.