It is well known that the renal nerve plays an important role in the regulation of renal functions such as sodium and water reabsorption in the tubules as well as in the pathogenesis of essential hypertension. The renal sympathetic nerves innervate to the basement membranes of almost all nephron segments. Specific adrenergic receptors and intracellular signal transduction systems are located in these nephron segments. By the recent progress of molecular biological techniques, at least three alpha 1-, three alpha 2- and three beta-adrenergic and five dopaminergic receptors have been identified and characterized. Using micromethods such as microperfusion, micropuncture techniques and the reverse transcription and polymerase chain reaction (RT-PCR) methods applied to the microdissected tubules, more detailed localizations and functions of these adrenergic and dopaminergic receptors are being classified. Future studies in this field may provide further information concerning the physiological and pathophysiological roles of these receptors in the kidney.