China has denounced Japan's new national security strategy, accusing it of military expansion.
Defence Ministry spokesman Geng Yansheng said in a statement that the move would increase regional tensions, state news agency Xinhua reported.
Earlier this week, Japan said it would buy advanced equipment including drones and amphibious vehicles.
It comes as Tokyo is embroiled in a bitter row with Beijing over islands in the East China Sea that both claim.
"China is firmly opposed to Japan's relevant actions," said Geng.
He accused Tokyo of using its national security as a pretext for military expansion.
The statement said Japan's security policy caused "great concerns" among neighbouring countries.
The announcement of more Japanese military spending came weeks after China established an air defence identification zone over a swathe of the East China Sea, including islands controlled by Japan. 
Prime Minister Shinzo Abe says he wants Japan to broaden the scope of activities performed by the military - something currently tightly controlled by the post-war constitution.
Over the five years, Japan plans to buy anti-missile destroyers, submarines, 52 amphibious vehicles, surveillance drones, US fighter planes and 17 Boeing Osprey aircraft, capable of vertical take-off. 
According to the Stockholm International Peace Research Institute, Japan ranks fifth in the world for military spending while China is in second place behind the US.