The ship, along with its sister, the Izumo, gives Japan's military greater ability to deploy beyond its shores.
Chinese Foreign Ministry spokeswoman, Hua Chunying, said that in recent years Japan had exaggerated the "China threat" as an excuse to expand its military.
"I also want to say that the Kaga was sunk by the US military in World War Two. Japan should learn the lessons of history," Hua told a daily news briefing, adding, "We hope the return of the Kaga is not trying to be the start of the ashes of Japanese militarism burning once more."
Japan’s second big helicopter carrier, the Kaga, entered service on Wednesday, giving the nation’s military greater ability to deploy beyond its shores as it pushes back against China’s growing influence in Asia.
Accompanied by a military band, Maritime Self Defense Force commanders took possession of the 248 meter (813.65 ft.) long vessel at the Japan Marine United shipyard in Yokohama near Tokyo, where it was docked next to its sister ship the Izumo.
Japan’s two biggest warships since World War Two are potent symbols of Prime Minister Shinzo Abe’s push to give the military a bigger international role. They are designated as helicopter destroyers to keep within the bounds of a war-renouncing constitution that forbids possession of offensive weapons.
In its biggest show of naval power in foreign waters in more than 70 years, Japan plans to dispatch the Izumo in May on a three-month tour through the South China Sea, sources with knowledge of the plan told Reuters earlier.
China claims almost all the disputed waters through which around $5 trillion of global sea-borne trade passes each year. Beijing’s growing military presence there has fueled concern in Tokyo and Washington.
Taiwan, Malaysia, Vietnam, the Philippines and Brunei also claim parts of the sea which has rich fishing grounds, oil and gas deposits. Japan has no claims there, but is locked in another territorial dispute with China over a group of islets in the neighboring East China Sea.
The addition of the Kaga means Japan will be able to mount overseas operations more often in the future. It will be based in Kure western Japan, which was home to Japan’s most famous World War Two battleship, the Yamato. The Izumo operates from Yokosuka near Tokyo, which is also where of the US Seventh Fleet’s carrier, the Ronald Reagan, is based.
The Japanese ships can operate up to nine helicopters each from their decks. They resemble the amphibious assault carriers used by US Marines, but lack their well deck for launching landing craft and other vessels.
