The Chinese navy said that it was conducting naval exercises in the East China Sea.
The move comes amid heightened tensions with Japan over the disputed Senkaku islands, which both countries claim but Japan controls.
BBC reported that the exercise involved 11 ships, including vessels from marine surveillance, and eight airplanes.
The drill was said to be a response to a nearby US-Japan military exercises in the region.
The US-Japan drill was reported by Japanese newspaper Asahi Shimbun, which said that the two countries would use the exercise to practice retaking the island if it was occupied.
The newspaper said that the drill was scheduled for early November.
The Wall Street Journal also reported that last month US marines were training Japanese ground forces in Guam.
Japan-China relations have recently deteriorated when Japan said that it would purchase three of the islands from private owners.
"Relations are worse than they have ever been in 40 years," Liu Jiangyong, a professor of Japanese politics at Tsinghua University in Beijing, told the Christian Science Monitor.
"I don't see much chance of a war; but I think Japan is preparing for one, and we should, too."
The BBC reported that Chinese television showed frigates, fighter airplanes and helicopters but did not give their location.
Xinhua reported that the exercises were meant to safeguard China's sovereignty and sharpen its response to emergencies.
China Daily summed up China's view of the exercises in their succinct headline: "Exercise to protect China."