Rice (Oryza sativa L.) plants can form a clonal plant network via clonal ramet and spacer. It has been demonstrated that clonal plant networks have physiological integration function. Chemicals and nutrients (such as photosynthetic assimilation product, mineral nutrients, water, etc.) can be transferred and shared among individuals in the same clonal plant network. Here we showed that anti-herbivore defense signals was shared among clonal plants of rice. When the main stem of wild type rice (donor) was fed by Cnaphalocrocis medinalis (rice leaffolder, LF) or treated with MeJA, weight gain of LF caterpillars on first order tiller (receptor) was significantly lower than that in the control group. The LF feeding on the main stem increased the activities of defense related enzymes including polyphenol oxidase (PPO), peroxidase (POD), superoxide dismutase (SOD), and lipoxygenase (LOX), and the content of trypsin proteinase inhibitor (TrypPIs) in the leaves of the main stem and primary tiller linked to the clonal network. Our results show that there exists defense signal transfer among clonal plants of rice, which may be important for protection of individuals in clonal plant networks.