Abstract: As one of the three macronutrients required by plants, potassium (K) participates in many physiological and biochemical processes in the body and is extremely important for plant growth and development. Research has been carried out on K⁺ absorption, transportation, and utilization by plants, especially the model plant Arabidopsis thaliana, with a particular focus on ion channels and transporters related to K⁺ absorption and transport. This article summarizes current research progress, especially that related to K⁺ channels and transporters, K⁺ absorption and transport, calcineurin B-like (CBL)-CBL-interacting protein kinase (CIPK) signaling pathway, and small signal molecules involved in signal transduction. This article also summarizes existing problems in K⁺ research and discusses future research directions.