Foreigners can legally buy property in China, and you do not need to be married to a Chinese citizen. The only requirement is to have been here 1 year on a residence permit. The most difficult part is convincing the people who continuously tell you that it is not possible.
If you require a mortgage then I believe you will not be able to purchase a newly developed property. I know a few people who have tried and failed. Possibly something to do with the developer bundling the mortgages together, and foreigners not being able to be part of that bundle. You can most definitely obtain a mortgage on a second hand property.
The only 2 differences from normal procedure that I am aware of are that you require authorisation from the government to purchase the property, and you must have a notarised translated copy of your passport. Both are easy to obtain. You may also have to prove your marital status, either by a sworn affidavit if you are single or a notarised translated copy of your marriage certificate.