A foreign citizen can enter China without a visa under any one of the following circumstances:

1) Direct Transit 

A foreign citizen who is transiting through China by air is exempted from a visa if he/she will stay only in the airport for no more than 24 hours and has a valid connecting ticket with confirmed seating on an international flight.

Citizens with passport or other international travel document, confirmed interline ticket and valid visa to the third country or region (if required) of the following 45 countries, can apply to stay in Beijing or Shanghai for 72 hours without visa on direct transit via Capital Airport, Shanghai Pudong Airport and Hongqiao Airport from January 1, 2013: 

Argentina, Austria, Australia, Belgium, Brazil, Brunei, Bulgaria, Canada, Chile, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Latvia, Lithuania, Luxembourg, Malta, Mexico, Netherlands, New Zealand, Poland, Portugal, Qatar, Romania, Russia, Singapore, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, United Arab Emirates, Ukraine, United Kingdom, United States. 

Citizens with passport or other international travel document, confirmed interline ticket and valid visa to the third country or region (if required) of the following 45 countries, can apply to stay in Guangdong Province for 72 hours without visa on direct transit via Guangzhou Baiyun Airport from August 1, 2013:  

Argentina, Austria, Australia, Belgium, Brazil, Brunei, Bulgaria, Canada, Chile, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Latvia, Lithuania, Luxembourg, Malta, Mexico, Netherlands, New Zealand, Poland, Portugal, Qatar, Romania, Russia, Singapore, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, United Arab Emirates, Ukraine, United Kingdom, United States. 

2) Visiting the Pearl River Delta or Hainan Island 

A. A foreign citizen holding an ordinary passport issued by any country with diplomatic relations with China is exempted from a visa if he or she is already in Hong Kong or Macao and joins a tourist group organized by a travel agency, which is registered in Hong Kong or Macao, for a visit to the Pearl River Delta region (including Guangzhou, Shenzhen, Zhuhai, Foshan, Dongguan, Zhongshan, Jiangmen, Zhaoqing and Huizhou) and his/her stay is no more than 6 days.

B. A foreign citizen holding an ordinary passport issued by any of the following countries is exempted from a visa if he or she joins a tourist group (of 5 or more persons) organized by an international travel agency registered in Hainan with the approval of China National Tourism Administration to visit Hainan Province and his/her stay is no more than 15 days: Australia, Austria, Canada, Denmark, Finland, France, Germany, Indonesia, Italy, Japan, Kazakhstan, Malaysia, Netherlands, New Zealand, Norway, Philippines, Republic of Korea, Russia, Singapore, Spain, Sweden, Switzerland, Thailand, the U.K., Ukraine and the United States of America.

Citizens of Germany, Republic of Korea and Russia may join an international tourist group (of 2 or more persons) and can stay up to 21 days.

3) Citizens of Singapore, Brunei and Japan 

A citizen of Singapore, Brunei or Japan with an ordinary passport is exempted from a visa if he/she visits China's mainland for tourism, business, or meeting with friends or relatives, and if he/she enters China through ports open to foreigners, and stays for no more than 15 days.

However, a visa is required for citizens of these three countries under any of the following circumstances:

A. An ordinary passport holder visits China for tourism, business, or meeting with friends or relatives, and stays for more than 15 days.

B. An ordinary passport holder visits China for the purpose of study, work, permanent residency, official visits and news coverage.

C. A Japanese citizen travels with a diplomatic or official passport.

4) Holders of Valid APEC Business Travel Card 

The APEC Business Travel Card is a substitute of a multiple-entry visa valid for 3 years. A card holder who presents a valid passport whose image and biographic data exactly matches that on the APEC Business Travel Card can enter China multiple times during the validity of the card for a stay of no more than 2 months each time.

5) Foreigner's Permanent Residence Card Holders 

6) Holders of Residence Permit for Foreigners issued by the Ministry of Public Security 

Foreign citizens entering China for the purpose of study or employment or as resident foreign journalists must apply for a residence permit at local public security authorities within 30 days of entry into China. Permit holders may stay in China and enter or exit China multiple times without the need of a visa during the validity period of the permit.

7) Bilateral Agreement 

Based on bilateral agreements signed or reached between China and foreign countries, foreign citizens of some countries who meet certain requirements may visit China without a visa. Please see the list of agreements on visa exemption signed between China and foreign countries for more information.

Source: www.china-embassy.org