Silver nanoparticles (AgNPs), owing to their excellent surface enhanced Raman scattering and broad-spectrum antimicrobial activities, are now attracting great interests for a wide range of biomedical applications.It has been reported that AgNPs could be used as a novel anti-tumor agent through the mechanisms involving oxidative stress, DNA damage, cell cycle arres.In addition, there are also some studies confirmed that AgNPs has a certain autophagy inducing effect, but the relationship between reactive oxygen species (ROS) and autophagy is still unclear.In the present study we discussed the autophagy inducing effect of AgNPs and how the autophagy was regulated by ROS in glioma cell line U251, seeking possible mechanisms by which AgNPs could achieve its autophagy inducing activity.Moreover, the autophagy inducing effect and ROS generation activity of silver ions was also carried out since silver ions are always released.