Xi 'an has several IELTS training centers, such as Huanya, New Channel and Lange. They are all doing IELTS, but I think the new channel is ok, because it is run by Hu Min. I have heard Hu Min's lectures before, and it feels good. Langer is a good advertisement, but everything else is just so-so. I don't know which branch school cheated all the students of their money. If you choose Langer, I suggest you be cautious. Huanya doesn't know much about it. You can do it yourself.