Relations between the two nations soured in recent weeks as a result of dispute over the ownership of the islands known as Senkaku in Japan and Diaoyu in China, which both nations along with Taiwan claim.
Widespread protests in China against Japan were held. In some cases people turned violent and attached Japanese car manufacturers.
Since then Japanese car manufacturers have said they will cut output to China.
“The worsening of exports reflected both the global slowdown and anti-Japan protests in China,” said Naoki Iizuka, from Citigroup Global Markets in Tokyo.