You must squat because Chinese toilets are in the ground in the form of a bowl or a trough (there are no toilet seats). American toilets are a rarity. Also, don't be surprised if there are no stall doors and flies buzzing around you as you are going.
Also, take PLENTY of toilet paper and SOAP (I recommend liquid soap in a travel-size plastic shampoo bottle) because toilet paper and soap are NEVER (well, very very rarely) provided.
I have heard they have installed American toilets in the Olympic stadiums but I have a feeling those will all be clogged. Every American toilet I ever saw in a public bathroom was clogged.