Astronauts Jing Haipeng, Liu Wang and Liu Yang transferred into the Tiangong-1 space lab module from their Shenzhou-9 spacecraft Monday about three hours after a successful automatic docking procedure, China's state-run Xinhua news agency reported.
"Shenzhou-9 crew members feel great!" Liu Wang reported to the Beijing Aerospace Control Center.
The three astronauts, including the country's first female astronaut Liu Yang, were launched into space from the Jiuquan Satellite Launch Center in northwest China's Gobi desert Saturday.
The astronauts are the first tenants in the 530-cubic-foot cabin of Tiangong-1, which has been orbiting the Earth for 262 days since its September 2011 launch.
The event is considered a major step forward in China's plans to build a space station by 2020, in time for the likely retirement of the International Space Station.