Hi Mr Zoe,
HKTDC is a B2B driectory, same as Alibaba, express, trade key and so on, there are quite a few of these directories around. You need to use the same principals when dealing with any of them to be safe. Despite any assurances given by the site itself or the supplier you are doing business with within the directory, always use a safe payment method and be extremely cautious in regards to branded products.
Cheers