The launch was carried out at 08:55 a.m. local time (12:55 GMT) from the Xichang Satellite Launch Center in southern Sichuan province, using a Chang Zheng-3B carrier rocket.
CASC noted that once the satellites reached the orbit and passed necessary tests, they would become part of the navigation system.
The BeiDou system is designed as a rival to GPS in the United States, GLONASS in Russia and Galileo in the European Union. Beijing plans that the system will offer its services worldwide by 2020.
This was the 319th mission for the Chang Zheng family of launch vehicles.