Your best bet, not knowing exactly what type of work will you seek, is to contact a few trading companies in Guangzhou and find out from them if they have any openings and / or any interest in you.  Of course, if you are know Mandarin will increase your chances for work.  And remember, to legally work in China you must have a "Z" work visa.

I think that there are two times a year when you might be able to scour up enough contacts in Guangzhou to make a viable run at this -- and that is when the Canton Trade Fair is on.  Go the trade fair, look at the stalls, talk to the different vendors and try to network well enough to find yourself a potential job.  This is an old, old established trade fair that has been going on for a very, very long time. 

i think it depends on
what kind of job do you want /
what are you good at / 
what language <s>do you speak /
what kind of trading are you doing now /
... ... ...

there are too many chances here in guangzhou, i just recomend you,first know what do you REALLY want, then you could  find a suitable job.