The vast zone, announced last week, crosses territory claimed by China, Japan, Taiwan and South Korea.
China has said all planes using the zone must file flight plans and identify themselves, or face "defensive emergency measures".
The US, Japan and South Korea say they have since defied the ruling.
The air defence identification zone (ADIZ) includes islands known as Senkaku in Japan and Diaoyu in China, which are claimed by Japan, China and Taiwan.
Its establishment has caused widespread anger, with the US calling it a "destabilising attempt to alter the status quo in the region".
Japan, the US and South Korea have all since flown military aircraft through the zone, and on Thursday, China announced it was deploying warplanes in the area.
Air Force spokesman Shen Jinke said that on Friday morning, Chinese pilots had identified two US surveillance aircrafts and 10 Japanese planes - including early warning aircraft, surveillance aircraft and fighter jets - crossing through the ADIZ, state media reports.
He made no reference to whether any further action was taken by any of the aircraft.
Earlier army spokesman Qin Gang said China had a right to patrol the region and that freedom of flight over the East China Sea was unaffected.
