"Our country's second aircraft carrier set sail from its dock in the Dalian shipyard for relevant waters to conduct a sea trial mission, mainly to inspect and verify the reliability and stability of mechanical systems and other equipment", Xinhua said.
Video footage aired by CCTV revealed the enforcing ship accompanied by a number of smaller sized military craft leaving a wharf and going out to sea under grey skies. The trials are meant to test the reliability and stability of its power system, Xinhua said.
China's first aircraft carrier, the Liaoning, arrived as a mostly empty hull from Ukraine and was commissioned in 2012 along with its flight wing of Chinese J-15 fighter jets.
The conventional-fuel-powered vessel is about 300 meters long.
Naval experts said the Chinese engineers and designers who built the ship had studied the most advanced military technology used by the Americans, as well as the former Soviet Union, and tried to incorporate it into the new ship to meet the practical needs of the PLA Navy.
Unlike the US Navy's longer-range nuclear carriers, both of China's feature Soviet-design ski-jump bows, meant to give fighter jets enough lift to take off.
Reports said China is also building its third aircraft carrier in Shanghai.
However, even with the potential development of further carriers, it could still be years before China's navy is able to deploy its fleet effectively, said Tsang.
Nevertheless, Beijing has actually started a comprehensive job to develop a "blue water" navy and modernise its 2 million-strong military, the world's biggest.
However it would still be no match in size or variety to the nuclear-powered vessels of the United States Navy, which has 11 providers.
China's defence budget rose 8.1 percent to 1.1 trillion yuan ($175 billion) in 2018, but it is still only about a quarter that of the United States.
The trials represent a landmark in Beijing's extensive project to modernize its navy as it continues to build up its presence in the disputed South China Sea and around Taiwan, which it sees as its own territory.