Important: Those who pass through two or more Chinese airports during their transit are strongly advised to first contact the immigration offices at the Chinese airports they need to pass through for information about whether or not they need a visa.

You need to apply for a visa unless you meet the following visa exemption requirements:
 
1. According to bilateral agreements, citizens of some countries (List of Agreements on Mutual Visa Exemption between the P.R. China and Foreign Countries) holding appropriate passports may enter China without a visa. 
 
2. Citizens of Singapore, Brunei and Japan holding ordinary passports may enter China without a visa through the ports of entry open to foreigners provided that they come to China for tourism, family visit, business or transit, and intend to stay in China for no more than 15 days. However, the following personnel of these three countries must apply for a visa in advance if:
(1) They are holders of ordinary passports, and come to China for tourism, family visit or business, and intend to stay more than 15 days;
(2) They are holders of ordinary passports, and come to China for study, employment, permanent residence or on a news reporting mission; and
(3) They are holders of Japanese diplomatic and service (official) passports. 
 According to the bilateral agreements, the diplomatic and service passport holders of Singapore, Brunei can stay in China for no more than 30 days without a Chinese visa.

3. Foreigners holding ordinary passports of the countries having diplomatic relations with China and on a tour to Hong Kong or Macao, and participating in group tours to the Zhu Jiang (Pearl River) Delta Area for a stay of no more than 6 days organized by the travel services legally registered in Hong Kong or Macao do not need to apply for a visa. The Zhu Jiang Delta Area refers to the administrative area of the following cities: Guangzhou, Shenzhen, Zhuhai, Foshan, Dongguan, Zhongshan, Jiangmen, Zhaoqing, and Huizhou. For going on a tour to Shantou, the aforementioned group is required to stay within the administrative area of Shantou and leave China from there directly. 

4. Foreigners who have confirmed onward tickets and seats on international flights and directly transit through China and stay for no more than 24 hours within the airport boundaries do not need to apply for a transit visa. However, anyone desiring to go beyond the airport boundaries temporarily should obtain permission from the immigration authorities at the airport. 
5. Sanctioned by the State Council, Shanghai Municipality, Jiangsu Province and Zhejiang Province, Beijing Municipality, Tianjin Municipality and Hebei Province, and certain ports in Liaoning Province are to adopt the 144-hour visa-exemption transit policy available to nationals from 53 countries. 144-hour Visa-free Transit Policy is valid for passport holders from the following countries: Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland, Russia, the United Kingdom, Ireland, Cyprus, Bulgaria, Romania, Ukraine, Serbia, Croatia, Bosnia and Herzegovina, Montenegro, Macedonia, Albania, Monaco, Belarus, the United States, Canada, Brazil, Mexico, Argentina, Chile, Australia, New Zealand, South Korea, Japan, Singapore Brunei, United Arab Emirates and Qatar.
http://www.mps.gov.cn/n2254996/n2254999/c5977739/content.html 
6. Citizens holding ordinary passports of the following 59 countries and on a group tour (minimum of five persons) to Hainan Province for a stay of no longer than 30 days, organized by international travel services approved by the National Tourism Administration of China and registered in Hainan Province, do not need to apply for a visa: Russia, the United Kingdom, Germany, Germany, Norway, Ukraine, Italy, Austria, Finland, Netherlands, Denmark, Switzerland, Sweden, Spain, Belgium, Czech Republic, Estonia, Greece, Hungary, Iceland, Latvia, Lithuania, Luxembourg, Malta, Poland , Portugal, Slovakia, Slovenia, Ireland, Cyprus, Bulgaria, Romania, Serbia, Croatia, Bosnia and Herzegovina, Montenegro, Macedonia, Albania, United States, Canada, Brazil, Mexico, Argentina, Chile, Australia, New Zealand, South Korea, Japan, Singapore, Malaysia, Thailand, Kazakhstan, Philippines, Indonesia, Brunei, United Arab,Emirates,Qatar,Monaco,Belarus.
http://www.mps.gov.cn/n2254996/n2254999/c6105863/content.html
7. Foreigners holding a valid Foreigner’s Permanent Residence Card of the PRC or Residence Permit for Foreigners in the PRC may enter China without a visa. 
8. Foreigners holding an APEC Business Travel Card may enter China without a visa.