Fast food in China is usually an American or other Western country's chain due to the fact that Western and American culture is perceived as being extremely cool. This means that the fast food restaurants, like McDonald's, KFC, Pizza Hut, Subway, etc, have to be very classy and sophisticated. If a Chinese Pizza Hut looked like the Pizza Hut on Penn Ave, a Chinese person would not set foot in it. The restaurants are well decorated, clean, well lit, have relaxing music playing, and the waiters and waitresses wear button down shirts and slacks.
The menus are also different from what is usually served in America. Pizza Hut also serves pasta, soup, steak, rice, and alcohol. KFC does not serve any of the sides (mashed potatoes, corn, bread, etc) that it does in the United States. It mainly serves sandwiches or chicken wings that can be spicy, grilled, or fried. They serve french fries, ice cream, and salads as well. McDonalds serves shrimp, salads, rice, and much smaller portions. The size of a small french fry in the US is the size of the large in China.
All of the fast food places also had to create a Chinese name for themselves. Burger King literally translated their name into "King Burger". Pizza Hut translated their name by sound so it sounds like "bi sheng ke". McDonalds also translated their name by sound. KFC did not have to translate their name because people in China do know the American alphabet, so KFC is still called KFC.
It also takes longer to eat a meal at a fast food restaurant in China. Part of this is due to the fact that the restaurant is seen as being sophisticated. To eat at Pizza Hut takes about an hour. You sit down, order, relax, and then your food is served to you in about 20 minutes or so. When a Chinese person wants to quickly grab something to eat on the go, they will stop by a street vendor that is nearby. Therefore, "Fast food" restaurants in China are not expected to provide food in less than a minute. There are also no drive throughs at Chinese fast food restaurants. Overall, the whole atmosphere of the restaurant is completely different from American fast food places.