China has launched its Shenzhou-15 spacecraft from the Gobi Desert, carrying astronauts to its newly-built Tiangong space station.
It will be the country's first-ever crew handover in orbit.
Three astronauts will live on the station for six months, before being replaced by another crew.
The station is becoming the second permanently-inhabited outpost in orbit, with the Nasa-led International Space Station the first.
China is not part of the International Space Station, and has been excluded since 2011 after the United States banned Nasa from interacting with the country.
China's plans to go to the Moon, Mars and beyond
The spacecraft Shenzhou-15 or "Divine Vessel" lifted off from the Jiuquan Satellite Launch Centre in the Gobi Desert in north-west China.
Tuesday's mission is the last of 11 required to assemble the station that is expected to operate for around a decade and run experiments in near-zero gravity.
The previous crew is expected to return to Earth in early December, after the handover.
A spokesperson for the China Manned Space Administration said the new crew would focus on installing equipment and facilities around the space station. Construction is expected to be complete by the end of the year.
China's space programme has previously landed robotic rovers on Mars and the Moon, and it was the third country to put humans in orbit.
Dr Christian Feichtinger, executive director of the International Astronautical Federation, told Chinese state television channel CCTV he thought "the world is actually watching" China's growing space capabilities.
The mission has offered Chinese citizens a chance to celebrate, as the country faces ongoing Covid lockdowns and protests. "Long live the motherland!" many wrote on social media.
The Shenzhou-15 team is led by 57-year-old Fei Junlong who previously commanded the Shenzhou-6 mission in 2005. It is his first time in space since then.
Over the next decade of the Tiangong's operation, it's expected China will launch two crewed missions to the station each year.
China has opened the selection process for astronauts for future missions to applicants from the "special administrative regions" of Macau and Hong Kong, who have previously been excluded.