Cell-to-cell and cell-to-environment communications are critical to the growth and development of plants.Cell surface-localized receptor-like kinases (RLKs) are mainly involved in sensing various extracellular signals to initiate their corresponding cellular responses.As important vegetative organs for higher plants to adapt to a terrestrial living situation,roots play a critical role for the survival of plants.It has been demonstrated that RLKs control many biological processes during root growth and development.In this review,we summarize several key regulatory processes during Arabidopsis root development in which RLKs play critical roles.We also put forward a number of relevant questions that are required to be explored in future studies.