Understanding the induced resistance to herbivory in plants is important in elucidating plant life-history traits. Resistance to herbivory takes two basic forms: defense and tolerance. Induced defense plays an important role in the ecology and evolution of plant-herbivore interactions. it has become increasingly clear that induced defenses to herbivory are complex traits involving the interaction of intrinsic and extrinsic factors. In this study, we investigated the effects of herbivory and the availability of light on induced resistance in Quetcus crispula saplings, and the relation between defense and tolerance involving photosynthesis and growth. We conducted field experiments with herbivorous insects under two light conditions. As an induced defense, the leaf mass per area increased with herbivory regardless of the amount of light available, and the concentration of condensed tannin was significantly higher when light was plentiful. On the other hand, as induced tolerance, the photosynthetic rate decreased with herbivory under conditions of ample light. In conclusion, we found that both the availability of light and herbivory affected defense and tolerance in Q. crispUa. In addition, we suggest that the interaction between defense and tolerance was noticeable when much light was available because of the photosynthetic reduction caused by herbivory.