Abstract: Plant ionomics is the study of elemental composition, distribution and accumulation in plants in relation to physiology, biotic and abiotic stimuli, development, environment and genetics with high-throughput elemental profiling. Ionomics is essential to identify quantitative trait loci, to predict physiological states and to identify potential genes responsible for the uptake, transport, and storage of elements in plants. In this review, we briefly introduce the concepts of ionome and ionomics, present the methodology currently used in ionomic study, and discuss the applications of plant ionomics. We also review the current issues and challenges in ionomics with a focus on prospects in this field.