It successfully docked with the core Tianhe module of the space station at 1408 GMT.
Next year, China will launch two additional core modules for the space station – Wentian and Mengtian – on Long March 5B rockets – China’s most powerful space transport vehicles.
The station, on completion, will rival the International Space Station (ISS), which is backed by countries including the United States, Russia and Japan. China was barred from participating in the ISS by the United States.
China began building the three-module space station in April with the deployment of Tianhe, followed by a three-month crewed mission that ended last week.
A Long March-7 rocket carrying the Tianzhou-3, or “Heavenly Vessel” in Chinese, blasted off at 3:10 p.m. Beijing time (0710 GMT) from the Wenchang Space Launch Center on the southern island of Hainan, state media reported.
Tianzhou-3 will deliver fuel and supplies for three astronauts due to travel to the Tianhe module in October. Their planned six-month stay would be the fifth mission in the series and the last for this year.
(Reporting by Liangping Gao and Ryan Woo; additional reporting by Tom Daly; Editing by Nick Macfie)