Abstract: Invasion of a grassland ecosystem by an alien plant usually results in loss of biodiversity, reduced vegetation productivity, and habitat deterioration of the grassland. A better understanding of the eco-physiological characteristics of the invasive plant is crucial for controlling these plant species effectively. As cutting is a commonly chosen method for controlling invasive plants both in China and elsewhere, this article reviews the eco-physiological patterns and mechanisms whereby invasive plants respond to defoliation. The main conclusions are as follows: (1) Defoliated invasive plants tend to adopt a compensatory photosynthesis pattern to ensure or improve their photosynthetic capacity. (2) A powerful stem/leaf regenerative ability of defoliated invasive plants can compensate rapidly for the loss of photosynthetic organs and above-ground biomass. (3) Change in the microbial community structure of soil after defoliation is more beneficial to the growth of defoliated invasive plants than to the native vegetation. (4) The defoliated invasive plants are able to utilize more efficient and diversified resource allocation strategies than the native vegetation to promote their regeneration. (5) A greater energy is distribution to the reproductive organs can help defoliated invasive plants maintain their population stability. (6) The tolerance to defoliation differs depending on the developmental stage of the invasive plant. Based on the above findings, we also analyze the advantages and disadvantages of cutting as a control treatment and make suggestions for controlling invasive plants using this method. In particular, researchers should focus on identifying the molecular mechanisms used by invasive plants to respond to defoliation, and on how invasive plants respond to global changes in the grazing rangeland, so as to develop efficient scientific methods for their control.