USA to Beijing to Hong Kong to USA

Hello,

My sister and I are traveling to Beijing from the United States arriving at 3:30pm November 3rd, 2016, staying the night, traveling to the great wall on a tour Friday all day, staying the night and then flying to Hong Kong 9am Saturday November 5th, then flying back to the United States November 9th 2016.

Do we need to acquire a visa if we have a valid passport?

I appreciate your time!

Erika