Abstract: Amino acids are the principal form of organic nitrogen transportation within plants. Amino acid transporters are essential for the import and export of amino acids from plant cells as well as between organelles across cellular or subcellular membranes. Various molecular mechanisms for the absorption and transportation of amino acids have been demonstrated in plants, which contribute significantly to nitrogen efficiency. This review summarizes research progress on the molecular mechanisms of amino acid transporters based on their expression pattern, function, and regulation, which are associated with important traits, such as nitrogen utilization efficiency, disease resistance, quality, and production.