South Manchuria Railway Zone
The South Manchuria Railway Zone (南満州鉄道附属地 Minami Manshū Tetsudō Fuzoku-chi?), or SMR Zone, was the area of Japanese extraterritorial rights in northeast China, in connection with the operation of the South Manchurian Railway.
Following the Japanese victory over Imperial Russia and the signing of the Treaty of Portsmouth, the South Manchuria branch (from Changchun to Lüshun) of the China Far East Railway was transferred to Japanese control. Japan claimed that this control included all the rights and privileges granted to Russia by China in the Li-Lobanov Treaty of 1896, as enlarged by the Kwantung Lease Agreement of 1898; which included absolute and exclusive administration within the railway zone.
The SMZ Zone was geographically a 62 meter wide strip of land on either side of the South Manchurian Railway tracks, extending along the 700 kilometer main trunk route from Dalian to Changchun, the 260 kilometer Mukden to Antung route, and four other spur routes, for a total length of 1100 kilometers, and a total land area of 250 square kilometers. These rail lines connected 25 cities and towns, and within each town the SMZ included warehouses, repair shops, coal mines and electrical facilities deemed necessary to maintain the trains. 
Japan stationed railway guards to provide security for the trains and tracks throughout the SMZ; however, these were regular Japanese soldiers, and they frequently carried on maneuvers outside the railway areas. In addition, Japan also maintained Consular Police attached to the Japanese consulates and branch consulates in major cities as Harbin, Tsitsihar, and Manchowli, as well as in the Chientao District, in which lived large numbers of ethnic Koreans.
In 1915, Japan presented to China the Twenty-One Demands resulting in the Sino-Japanese Treaty of 1915. The treaty provided that Japanese subjects would be free to reside and travel in South Manchuria and engage in business and manufacture of any kind, and could lease land necessary for erecting suitable buildings for trade, manufacturing and agricultural enterprises. Japan loosely interpreted this to include most of Manchuria in the term "South Manchuria".
After the foundation of Manchukuo, with full Japanese control over all of Manchuria, the SMZ ceased to have a function, and was abolished in 1937.
- Coox, Alvin (1990). Nomonhan: Japan Against Russia, 1939. Stanford University Press. ISBN 0-8047-1835-0.
- Young, Louise (1999). Japan's Total Empire: Manchuria and the Culture of Wartime Imperialism. University of California Press. ISBN 0-520-21934-1.
- Coox, Nomonhan, pp.3