There are three cosmonauts on board.
The launch took place from the Jiuquan space center in Gansu province in northwestern China.
The Shenzhou-12 entered orbit and the launch has been recognized as successful, according to a Chinese manned flight program report.
Beijing successfully sent up the core module of its first space outpost, Tiangong, in late April. China state-run media report that it will take 12 missions to assemble the space station in lower Earth orbit, with the construction set to be completed by the end of 2022.