The Chinese–Russian border or the Sino-Russian border is the international border between China and Russia. After the final demarcation carried out in the early 2000s, it measures 4,209.3 kilometres (2,615.5 mi), and is the world's sixth-longest international border. According to the Russian border agency, as of October 1, 2013, there are more than 160 land border crossings between Russia and China, all of these border crossings are open 24 hours. There are crossing points established by the treaty including railway crossings, highway crossings, river crossing, and mostly ferry crossings.

A triple border, tripoint, trijunction, triple point, or tri-border area is a geographical point at which the boundaries of three countries or subnational entities meet. There are 175 international tripoints as of 2020. Nearly half are situated in rivers, lakes or seas. On dry land, the exact tripoints may be indicated by markers or pillars, and occasionally by larger monuments.