Three Japanese scientists won the award this year along with one Japanese-born American.

Japan's past record was set in 2002, when two Japanese were awarded Nobel prizes for physics and chemistry. Osamu Shimomura was awarded the Nobel prize for chemistry on Wednesday, and Japanese scientists Toshihide Maskawa and Makoto Kobayashi, along with Yoichiro Nambu, a Japanese-born American citizen, won the Nobel for physics on Tuesday.

"Honestly, I'm truly amazed that we had four laureates in one year. It's incredible," Aso told reporters.

Kobayashi and Maskawa, who both live in Japan, took half the physics prize for a 1972 theory that forecast the later discovery of a new family of subatomic particles. Yoichiro Nambu of the University of Chicago shared the prize with them for his mathematical research in the field of symmetry.

Shimomura, who lives in Boston, was awarded the chemistry prize along with two Americans for discovering and developing a glowing jellyfish protein that revolutionized the ability to study disease and normal development in living organisms.

Science and Technology Minister Seiko Noda said the haul was an "unprecedented" achievement.

"They demonstrate Japan's underlying power, giving us enormous encouragement," Noda said.

Sixteen Japanese have won Nobel prizes since 1949.