Japan's defence minister Nobuo Kishi said it involved five ballistic missiles fired by China as part of an unprecedented live-fire military drill in six areas surrounding Taiwan.
The show of force comes a day after the US House of Representatives Speaker Nancy Pelosi visited the self-ruled island Beijing regards as its sovereign territory.
The White House has condemned China's decision to launch live missiles near Taiwan as irresponsible and believes that Beijing will continue to react in the coming days.
China's state broadcaster CCTV says the drills will run until Sunday.
Images released by the Chinese military show what appear to be long-range live-fire drills from undisclosed locations.