Duke University Library has a sizable collection of pictorial works (most of them are photographs reprinted in books) about China. The following are selected online archives and resouces:

• Sidney D. Gamble Photographs from Duke's special collection, approximately 5000 photographs, 1917-1932.
• AGSL Digital Photo Archive about 3,500 images from the American Geographical Society (AGS) Library. Photographers include Harrison Forman(1904-1978), Bert A. Krawczyk, Clarence W. Sorensen andMary Jo Read, etc.
  
• Bucklin China Archive - Looking at China in 1924 : In 1923, Harold Bucklin took his family Shanghai and produced an exquisite body of work of large format photographs of Pre-Revolutionary China using a Graflex camera.
• China: A Traveling Exhibit 1903-1904: R. Harvey Sargent, a topographer with the U.S. Geological Survey, joined
  a Carnegie Institutionresearch mission that took him 1,800 miles across the vast interior of China. Along the way, Sargent documented his observations with photographs of the land and the peasants from which the Chinese Revolution was to come.
• Gerald & Rella Warner Manchuria Negatives : US Vice Consul to Mukden (Shenyang) Gerald Warner created these 298 photographs between March 22, 1934 and August 2, 1935.
• Historical Photographs of China A joint project by School of Humanities, University of Bristol, UK & Institut d'Asie Orientale (IAO), Lyon, France. The archived collections include a Chinese diplomat, foreign businessmen, staff of the administrations in the Chinese treaty ports, missionaries, and officials of the Chinese Maritime Customs Service.
• Historical Photographs of China 中国摄影史图片库 part of the site by Thomas H. Hahn, collections are on China or relate to China, including The Yuanmingyuan, Early Photographs of Taoist Sites and Practice 道教旧影, etc.
• International Mission Photography : historical images from Protestant and Catholic missionary collections in Britain, Norway, Germany, France, Switzerland, and the United States. The photographs, which range in time from the middle of the nineteenth to the middle of the twentieth century, offer a visual record of missionary activities and experiences in Africa, China(10,000 images), Madagascar, India, Papua-New Guinea, and the Caribbean. You can browse by places or search by keywords, collections, and places.
• Virtual Shanghai is part of the IAO-Databases Project and contains 4,000 images(mostly before 1949). The images contain basic metadata (often including a short description) and are searchable according to the following criteria: title/subject; date; estimated periods; location; action; caption on print; caption on support; support; author; nature; repository, and general keywords. The Live Map presents images of Shanghai onn a GIS map. 
• Taiwan
  
  • Gerald & Rella Warner Postcards: collected in Taiwan by Gerald and Rella Warner during Gerald's service as US Consul between August 26, 1937 and March 8, 1941. Warner Taiwan Postcards contains 201 postcards and 139 b/w commercial photographs from that periodA photographic record of a US consul's impressions of urban and rural life in Taiwan under Japanese colonial rule.
  • Gerald & Rella Warner Taiwan Negatives : US Consul to Taiwan Gerald Warner and his wife Rella created these 369 photographic negatives between August 26, 1937 and March 8, 1941.
  • Scenic Taiwan Book : 'Taiwan no fūkō' (Scenic Taiwan) 台湾の風光 is one of many photo albums published in the 1930s that depict different areas of the Japanese Empire.  This particular volume was published in Wakayama Prefecture in or after 1938. Its editor, one Yamazaki Kin'ichirō (or Kane'ichirō) (1897-1985), published several albums of Taiwan, Manchuria, and Hokkaidō photographs in this same decade. 'Scenic Taiwan' extols the good results of Japanese colonial rule, both in picture and in text.  This digital version features the editor's translations of all captions, along with the original Japanese, providing a resource for studies in colonial architecture, discourse, and East Asian folkways.
  • Taiwan Photographic Monthly Periodical : The Taiwan shashinchō 台湾写真帳 (Taiwan Photograph Album) was published monthly from November 1914 through December 1915, for a total of 14 issues.  The 468 pages captured for this collection include reprints of photographs from other Japanese publications, and many unique photographs.
  • Taiwan Memory 台湾记忆 ：image part of Taiwan memory site from the National Central library of Taiwan.

1949-1966

• Korean War Historical Images a Flicker site of images from the Korean War. Credit Department of Defense and photographer (see attached captions.)

1966-1976 Cultural Revolution:

• China 1972 [Cultural Revolution] Image Database 'Serve the People': Daily Life in China During the Cultural Revolution (1972)
• Images from Cultural Revolution 文化大革命图片库 : part of the site by Thomas H. Hahn in 12 subjects like The anti-Kong anti-Lin campaign in Qufu, etc.
• Morning Sun: A film and website about cultural revolution with photographs, art images and Mao Badges
• Thomas H. Hahn Docu-Images - Images from the Cultural Revolution : a collection of Xinhua News Agency photographs from the late 1960s to the mid-1970s.
• China 1972 [Cultural Revolution] Image Database 'Serve the People': Daily Life in China During the Cultural
  Revolution (1972)
• Tibet
  • The Tibet Album: British Photography in Central Tibet 1920-1950
  • Tibet - American Geographical Society Library: selection of historical maps and photographs of Tibet from the holdings of the American Geographical Society (AGS) Library. The collection consists of 1,090 images. It includes a unique set of 50 photographs of central Tibet and Lhasa taken by two Mongolian Buddhists, G. Ts. Tsybikoff and Ovshe Norzunoff, who visited Tibet in 1900 and 1901. The photographs represent the first photographic images of Potala Palace in Lhasa and other Tibetan monasteries. In addition, over 1,000 images of Tibet have been drawn from the extensive photographic collection of Harrison Forman. Photojournalist and explorer, Forman undertook three expeditions to remote areas of northern Tibet between 1932 and 1937.

Post-1980 :

• Chinese contemporary photography: a virtual exhibition of a private collection of 150 works from 40 artists.
• Contemporary Chinese Photography : part of the Conscientious site with 28 Chinese artists' works.
• New Chinese Art: contemporary Chinese photography : has works of 17 Chinese artists, no information on the artists.

China in general:

• A Visual Sourcebook of Chinese Civilization mainly for K-12 education.
• Chinese Cultural Studies: ImagesThis page contains a summary of all the picture files available on Brooklyn College Core 9 Chinese Culture Web site." Maintained by Paul Halsall, Brooklyn College.
• Hong Kong Picture Archive
• Scenery Pictures of China(CND InfoBase)Tourist shots divided into three series. The first, "The Land of Beauty," includes the "top ten scenic sites." The second series is of "Natural Landscapes," and the third is "Ancient Buildings." Also includes links to other sites with pictures of China, including a lot of good modern Hangzhou scenes and Time Magazine's "A Day in the Life of China." 
• World Bank Photo Library A unique collection of over 50,000 images featuring global development.
• 人民网图片 part of 人民网.