Short answers, pulled from the story.
China and Russia established diplomatic relations after the dissolution of the Soviet Union in 1991. The two countries signed the Treaty of Good-Neighborliness and Friendly Cooperation in 2001, and in 2019 upgraded their relationship to a "comprehensive strategic partnership of coordination for a new era."
Annual trade between China and Russia reached a record $245 billion in 2024 before declining to $234 billion in 2025. China is by far Russia's largest trading partner, accounting for 57% of Russia's imports and 31% of its exports.
The Power of Siberia is a natural gas pipeline connecting Russian fields to China, covered under a 30-year gas deal worth $400 billion signed in 2014, the largest in the history of Russia's gas industry. Deliveries began in late 2019, and the full pipeline was completed in December 2024. As of 2024, Russian crude oil accounted for nearly 20% of China's total energy imports.
China and Russia are not formal military allies. Both governments have officially declared their relationship "Not allies, but better than allies." In March 2023, Putin stated publicly that there is no military alliance between the two countries, though in November 2024 he called China an ally.
The Sino-Soviet split of 1961 turned China and the Soviet Union from Cold War allies into rivals competing for control of the worldwide Communist movement. A major war between the two was a serious possibility in the early 1960s, and a brief border war did take place in 1969. Relations remained poor until the dissolution of the Soviet Union in 1991.
Following Russia's 2022 invasion of Ukraine, trade between the two countries hit a record $190 billion that year, and Chinese car brands grew from 18% to 57.2% of Russia's car market by 2025. The share of Russian exports paid in Chinese yuan rose from 0.4% before the invasion to 16% by December 2022, and by end of 2023 more than 90% of bilateral trade was conducted in yuan or rubles.