He said the search area was established with a dimension of 1,575 sq nautical miles, Xinhua cited from a tweet by the navy chief.
"This is most likely the area of the missing plane," he added, posting an image mapping out the search area.
He said three ships were tasked to search there and the Indonesian National Search and Rescue Agency had assigned diving teams to carry out diving and underwater search.
AirAsia flight carrying 162 passengers had crashed in Java Sea where rescue operations are still on. Officials have found 40 bodies so far and are now trying to locate the black box belonging to the flight.