A patrol plane that was dispatched after a distress call Tuesday spotted the capsized 105-ton Shen Lian Cheng 707 about 330 kilometers (205 miles) north of Ishigaki Island, a southern island near the Japanese-controlled Senkakus.
Five of its 10 crew members were rescued Tuesday by another Chinese boat passing nearby, the Japanese coast guard said, quoting information provided by Chinese maritime authorities.
A Japanese patrol ship is still searching for the five missing Wednesday.
The fishing boat’s activity and movement or the cause of the capsizing was not known. Weather in the area was windy with rough waves at the time of the capsizing Tuesday morning.
Ishigaki is north of the Japanese-controlled Senkaku Islands, also claimed by China and called Diaoyu.
China has increased maritime activity in the region, triggering Japanese security concerns.