PROBLEM TO BE SOLVED: To provide a rice germ fermented liquid and a rice germ fermented powder as materials, which are produced by using general food materials and have a biological immune system reinforcement effect, an antitumor effect, and an antiviral infection effect； and a method for producing the rice fermented liquid/power.SOLUTION: The rice germ fermented liquid and the rice germ fermented powder are prepared by adding water, glutaminic acid or glutamate, and lactic acid bacteria to rice germs or rice bran containing rice germs, fermenting the mixture at a fixed temperature, and then, squeezing the fermented mixture and filtrating the resultant juice. The rice germ fermented liquid and the rice germ fermented powder comprise gamma-aminobutyric acid and rice germ/bran derived components.
