First off when a house is bought in China, the land is still owned by the government. The buyer is essentially renting the land. What the buyer owns is the space between the walls but not the actual land it sits on.
Another concept that is worth considering is the fact that the real estate market in China moves much faster than most western countries. This is because in China people usually pay for properties in cash. Loans and mortgages are less utilized which makes the process of buying a house much faster.
It is important to understand that there are extra costs when buying a property in China as a foreigner. To get a loan in China as an expatriate may be very difficult and time consuming. Also owning a property in China does not give you the right to residency. It might be a good idea to check the current visa policy before buying a property in China.