Western media reports this week said China is building a second carrier in Shanghai and it will be launched late this year.
"Such reports are inaccurate," Yang said.
China's first aircraft carrier was delivered and commissioned for the People's Liberation Army (PLA) Navy on Tuesday.
The carrier, refitted from the Soviet-built warship Varyag, was renamed Liaoning and underwent years of refitting and sea trials.
The 1,000-ft vessel is designed to carry 26 aircraft and 24 helicopters.