Northeast China
Manchurian - They played a major role in Chinese history eg. Qing Dynasty. They are mostly found in Northeast China.
Russian - The cultures can be seen in Inner Mongolia and Heilongjiang provinces. There are two railway crossings at Mazhouli and Suifenhe to allow the access of the Russians. Harbin, Heilongjiang is notable for its beautiful ice sculpture festival in the winter. Many Russian tourists come over to have fun.
Mongolian - They reside in Inner Mongolia. They are strong in their own cultures like having the photo of Genghis Khan hanging on the wall everywhere - even inside their household. They played a part in Chinese history. Eg. Yuan Dynasty. There are plains there for them for horse riding. Traditional festival like Naadam held there too.
Northwest China
Desert, Oasis, camels ... Sounds like Arab country right ? Indeed, Northwest regions are mostly Muslim. You can have a taste of Middle East cuisine like Shawarma. Some of their mosque there has unique Chinese architectures. It is a very interesting place to visit.
Southern China
Hong Kong, Special Administration Region of China - It is established in 1997 after British handover. There are some British cultures being spread over there. The countrymen are able to speak English and there are many churches around the region. English roadsigns are everywhere - it will be easy for travellers.
Macau, Special Administration Region of China - Another SAR of China. It is established in 1999 after Portuguese handover. It is a very small region. It is also known for Eastern Las Vegas strip. There is many casinos clustered in one area. The older generation are able to speak Portuguese. Ruins of St Paul is the trademark of that region and the egg-tarts are great.
Korean - Once you reach Yanbian in Jilin, Korean culture kicks in. It borders North Korea. The signboard are in Korean too. There will be Korean festivals held there too.
Central China
If you think Indian food is the spiciest, you can try Mala Steamboat. It is so spicy that it burns you inside out. Your stomach will feel the sharp burn after sipping the soup. Sichuan is the province that is known for that. You challenge yourself there with the Chinese.
West China
Himalaya region - none other than Tibet. If you are a Buddhist, you will love it. It has a very high altitude in the region. The oxygen is thin and the environment is cooling there. There is a Potala Palace there with long history. Devotee pray everywhere in the city of Lhasa. There lives a well-known priest - Dalai Lama
In a nutshell, I have sum up everything. So how many 'countries' have you visited in China ? You just need to know Mandarin and you are able to travel around in China.