Rare earth ore mining and smelting, application of rare earth elements in farm lead to accumulation of rare earth elements in soil, and affect the structure and function stability of farmland ecosystem. This article reviews the main source, distribution and output of rare earth elements in farmland, the determination method of rare earth elements in soils and plants, and the effect of rare earth elements on crops, microorganisms, animal and human health in farmland ecosystem. Rare earth element toxicity evaluation and rare earth contaminated soil remediation of farmland ecosystem are discussed in the paper. Finally some problems will be pay attention to studying of rare earth elements on farmland ecosystem in the future.