The Chinese-Russian border (Sino-Russian border) is the international border between the People's Republic of China and the Russian Federation. It is the world's sixth-longest international border. It consists of two sections: the long eastern section and the much shorter western section.
The eastern border section is over 3500 kilometres in length, with its true length only having been established in 1999 following a joint venture, and measured as 4,195 kilometres (2,607 mi). It starts at the eastern China - Mongolia - Russia tripoint ( ) and runs north-east, followed by south-east along the Argun and Amur rivers, and finally south-west along the Tumen River to the border with North Korea at ( ), only a few kilometres before the river flows into the Pacific Ocean.
The much shorter western border section is between Russia's Altai Republic and China's Xinjiang. Its western end is the China-Kazakhstan-Russia tripoint, and the eastern end, the tripoint with Mongolia.
The border itself, as well as the Russian-Chinese relations, has a long and rather conflicting story that began with the conquest of Siberia. Today's Sino-Russian border line is mostly inherited by Russia (with minor adjustments) from the Soviet Union, while the Sino-Soviet border line was essentially the same as the border between the Russian and Qing Empires, settled by a number of treaties in 17th through 19th century. Below is the list of important border treaties, along with the indication as to which sections today's Sino-Russian border were largely set by them:
- Treaty of Nerchinsk (1689) (the border along the Argun River)
- Treaty of Aigun (1858) (the border along the Amur River)
- Convention of Peking (1860) (the border south of today's Khabarovsk)
- Protocol of Chuguchak (1864) (the western section of the border)
- Treaty of Saint Petersburg (1881)
Post-1917, territorial and political expansion of Russia, as well as China, have been the occasion for mutual territorial claims:
During 1968, the Soviet Army had amassed along the 4,380 km (2,738 mi.) border with China — especially at the Xinjiang frontier, in north-west China, where the Soviets might readily induce Turkic separatists to insurrection. Militarily, in 1961, the USSR had 12 divisions and 200 aeroplanes at that border; in 1968, there were 25 divisions, 1,200 aeroplanes, and 120 medium-range missiles. Moreover, although China had exploded its first nuclear weapon (the 596 Test), in October 1964, at Lop Nur basin, the People's Liberation Army was militarily inferior to the Soviet Army. By March 1969, Sino-Russian border politics became the Sino-Soviet border conflict at the Ussuri River and on Damansky–Zhenbao Island; more small-scale warfare occurred at Tielieketi in August. In The Coming War Between Russia and China (1969), US journalist Harrison Salisbury reported that Soviet sources implied a possible first strike against the Lop Nur basin nuclear weapons testing site. The John F. Kennedy and Lyndon B. Johnson administrations had considered attempting to destroy the Chinese program before it succeeded, but the USSR had refused to cooperate. Now the U.S. warned the USSR that a nuclear attack against China would precipitate a world-wide war, and the USSR relented. Aware of that possibility, China built large-scale underground shelters, such as Beijing’s Underground City, and military shelters such as the Underground Project 131 command center, in Hubei, and the "816 Project" nuclear research center in Fuling, Chongqing.
Heavily militarised following the Sino-Soviet split of the 1950s and 60s, culminating in the Sino-Soviet border conflict of 1969, the border slowly opened after 1982 allowing the first exchange of goods between the two countries. Between 1988 and 1992 the cross-border commerce between Russia and the Heilongjiang province increased threefold, with the number of legal Chinese workers in Russia increasing from 1286 to 18905.
In 1990-91, Russia and China agreed to withdraw their military from their heavily fortified positions along their extensive border, including in the sensitive Tumen River area. Major navy and army facilities in Khasan District, Russia, were dismantled. Sino-Russian border trade resumed as early as 1983-85, but accelerated in 1990-91, when border crossings were re-opened to private traders and travellers, Vladivostok was declared an open city, and foreigners were able to travel freely to the border regions of both countries. In 1991, China also began a new round of economic reforms, and introduced new measures to accelerate foreign investment, which began to have a favourable impact in the Tumen River area. Similarly, in early 1992, China announced border trade incentives and the introduction of special border economic zones along the Sino-Russian border, including its largest, in Hunchun.
On May 29, 1994 During the visit of Russian Prime Minister Viktor Chernomyrdin to Beijing, Russian and Chinese officials sign an Agreement on the Sino-Russian Border Management System intended to facilitate border trade and hinder criminal activity. On September 3 that year, a demarcation agreement was signed fixing the boundary along a disputed 55-km stretch of the western Sino-Russian border.
In November 1997 at a summit meeting in Beijing, President Boris Yeltsin and General Secretary and President Jiang Zemin signed an agreement settling the demarcation of the disputed 4300-km eastern sector of the Russian–Chinese border in accordance with the provisions of a May 1991 demarcation agreement between China and the Soviet Union.
The 2004 Complementary Agreement between the People's Republic of China and the Russian Federation on the Eastern Section of the China–Russia Boundary stated that Russia agrees to transfer a part of Abagaitu Islet, whole Yinlong (Tarabarov) Island, about a half of Bolshoy Ussuriysky Island and some adjacent islets to China. A border dispute between Russia and China, standing since Japanese invasion of Manchuria of 1931, was resolved. These Amur River islands were until then administered by Russia and claimed by China. The event was meant to foster feelings of reconciliation and cooperation between the two countries by their leaders. The transfer has been ratified by both the Chinese National People's Congress and the Russian State Duma. The official transfer ceremony was held on-site October 14, 2008.
The Republic of China, based on Taiwan, refused to relinquish its claims to parts of disputed islands remained in Russian possession.
According to Russian media, the main problems today are the illegal labor migration of Chinese citizens, smuggling and illegal fishing by Chinese citizens in Russia, as well as an active construction, which the Chinese side is on the south bank of the river, causing erosion of the low-lying Russian river bank.
Border crossings 
There are a number of highway and ferry border crossings on the eastern section of the binational border. There are also two railway crossings, at Zabaikalsk/Manzhouli and Suifenhe/Grodekovo; both are over a century old, brought into existence by the original design of Russia's Transsiberian Railway that took a shortcut across Manchuria (the Chinese Eastern Railway). The third railway crossing, near Hunchun/Makhalino, operated between 2000-2004, but is closed now; plans for its reopening are being considered.
As of 2009, there were no border crossings of any kind on the two countries' short and remote western border section.
- Sébastien Colin, Le développement des relations frontalières entre la Chine et la Russie, études du CERI n°96, July 2003.
- НАЧАЛО РУССКО-КИТАЙСКОГО РАЗГРАНИЧЕНИЯ В ЦЕНТРАЛЬНОЙ АЗИИ. ЧУГУЧАКСКИЙ ПРОТОКОЛ 1864 г.
- Mueller, Jason: Evolution of the First Strike Doctrine in the Nuclear Era, Volume 3: 1965–1972
- Burr, W.; Richelson, J. T. (2000–2001). "Whether to "Strangle the Baby in the Cradle": The United States and the Chinese Nuclear Program, 1960-64". International Security 25 (3): 54–99. doi:10.2307.2F2626706. JSTOR 2626706.
- Andrew Osborn and Peter Foster, 13 May 2010, USSR planned nuclear attack on China in 1969, Telegraph UK
- Chronology of principal defence and security-related agreements and initiatives involving the Russian Federation and Asian countries, 1992–99
- Дополнительное соглашение между Российской Федерацией и Китайской Народной Республикой о российско-китайской государственной границе на ее Восточной части. October 14, 2004 (Russian)
- Переход Махалино–Хуньчунь (Makhalino-Hunchun border crossing), 2011-08-12 (Russian)
- Россия и Китай реанимируют бездействующий погранпереход (Russia and China will revive a defunct border crossing), 20.09.2012 (Russian)
- See e.g. the apparently exhaustive list of China's border crossing in Xinjiang (新疆边贸口岸信息汇总, 2009-05-07), which includes no crossings on the border with Russia)