If you apply the Qantas Frequent Flyer Out of Australia and New Zealand, it is free of charge, and if you fly with Qantas, you will gain the points, You can gain free air ticket subjected to your points.
You can chioce your region by China and input your China address then they will send your frequent number by email and some plate by mail.
Please note no annual charge for Qantas Frequent Flyer.