As a general rule about buying from china, branded items are a big no no!
what exactly are you looking for?
where are you located?
ali baba is only a trading platform, this does not mean that the suppliers are trustworthy or have good intentions.
Although only a small percentage of suppliers from china are scammers they all show up on these trading platform websites.
personally i would not look at anyone on alibaba unless they have minimum of 4 years gold membership.
I would also only pay by credit card and make sure my payment is covered by the card company.