Abstract: Reactive oxygen species(ROS) mainly produced by oxidative stress, not only causes DNA damage and genetic unstability, but also closely involves in organ lesion and tumor development. Recently, taking advantage of ROS difference between the normal cells and tumor cells, ROS responsive nano-delivery system is designed. Drugs only release within the tumor micro-environment at high level of ROS, which ensures high selectivity and therapeutic efficacy. The newly progress made in this field will be briefly discussed in this paper.