A defence review paper says Japan needs marines and surveillance drones, plus better missile defence capabilities.
The paper also called for better defences against missile attacks and the potential to attack enemy bases.
The interim report is part of a defence review ordered by prime minister Shinzo Abe, with final proposals due by December.
On Sunday, Mr Abe won control of Japan's Upper House, meaning he is now in a stronger position to reshape Japan's current defence strategy.
The BBC reports he is looking to expand the scope of Japan's military activities.
Under Article 9 of its post-war constitution, Japan is blocked from the use of force to resolve conflicts except in the case of self-defence.
But Mr Abe has indicated he wants to re-examine the role of Japan's military to meet the changing security environment in the Asia-Pacific region.
This will guide the focus of the direction that the Self Defence Forces should be heading going forward," said defence minister Itsunori Onodera.
The report said amphibious units that could be dispatched quickly to remote islands were needed and surveillance equipment.
"Japan needs to enhance its ability to respond to ballistic missile attacks in a comprehensive manner," Kyodo news agency quoted the report as saying.
Japan and China are locked in a dispute with over East China Sea islands known as Senkaku in Japan and Diaoyu in China.
Japan controls the islands but the BBC reports Chinese ships have been sailing in and out of what Japan says are its territorial waters since late last year.
Japan has also voiced concern over increases in military spending by China.