The legislation was passed by the parliament's upper house, having cleared the lower house last month.
The move marks a victory for Prime Minister Shinzo Abe, who has made revising the constitution one of his top priorities, correspondents say.
The current constitution has not been changed since 1947.
Drawn up by the
But Mr Abe wants
Mixed opinions
Mr Abe's ruling Liberal Democratic Party (LDP) is working on a draft of a new constitution.
The legislation passed by parliament says that a referendum on the issue cannot take place before 2010, and needs approval from a majority of voters.
"Since this will take effect in three years, what is important is to deepen the debate among the people even further," Chief Cabinet Secretary Yasuhisa Shiozaki said.
Public opinion in
Four opposition groups - including the main opposition Democratic Party of Japan (DPJ) - opposed the bill because of divided public sentiment on the issue,
Critics of the proposed changes say the pacifist constitution has kept
The move may also meet concern from
Under former Prime Minister Junichiro Koizumi, this was pushed still further, to allow troops to join peacekeeping missions in
Photo caption
Soldiers from the Japanese Ground Self Defense Force in