Increasing concentrations of atmospheric CO₂ are predicted to impact both current and future ecosystems, which have been greatly concerned by scientists. Elevated CO₂ not only affects the growth and development of plants, but cause changes in the structure and contents of their chemical components that resulted in the changes of the growth and development of herbivore insects fed on plant. Moreover, natural enemies, which prey these herbivore insects, may also be impacted because of the effects of elevated CO₂ on host plant and herbivore insects through food chains.In this overview, we reviewed the progress of research in impacts of elevated CO₂ on insects, introduced the research methods of the effects of elevated CO₂ on the plant-insect systems, generalized the regularity and mechanisms of elevated CO₂ on herbivore insects and their natural enemies, explored the characteristics of the changes in atmospheric CO₂ concentrations on the interactions between plants and herbivore insects, analyzed the existing issues in the research in the impacts of elevated CO₂ on insects, and listed critical areas of research about the impacts of elevated CO₂ on insects in the future based on the domestic and foreign research reports.