Abstract: Minirhizotron (MR) devices are playing an important role in fine root study due to their convenience, low time-input requirement, also because they can be used in situ. The fine roots of grassland plants are important in the soil nutrient cycle and in the sustainable development of grassland. Therefore, this review summarized the progress of research into fine root dynamics of plants in grassland. Aspects covered include the effect of global climate change, land use, land management and soil organisms on root longevity and root turnover rate. Most studies indicated that high CO₂ concentration, and also global warming, increased root length, root number or biomass, but decreased root longevity. Fine roots developed in spring tend to have greater longevity than those developed in autumn. Additionally, grazing and nitrogen fertilizer have no effect on plant root growth, but increase shoot biomass, and decrease the species diversity in natural grassland. Plant fine root longevity is positively correlated with root diameter, whereas root turnover rate is negatively correlated with root diameter. The future research directions for MR research include study of: 1) the relationship between grazing, land-use change, soil organism populations and plant root dynamics in grassland; 2) the effect of root longevity and root turnover rate on the soil carbon and soil nutrient pool; 3) the mechanisms where by interaction between climate change and human activity affect plant root systems; and 4) how external factors influence the relationship between plant roots and soil organisms. We expect to raise awareness of the application of MR technology in the grassland agro-ecosystem research, and to advance the development of fine root research in grasslands.