In summary, the direct evidence is provided that NBs increase the production ROS inside barley seeds during the germination process. NBs could not only produce the ROS in the water, they could also increase the ROS production inside seed. From our research above comes out a novel mechanism for NBs’ promotion effect on physiological activity of living organisms. Once fully understanding NBs’ effect on living organism growth is achieved, the manipulation of NBs will develop a new technology in agricultural applications.