lt had been reproted previously that (${pm}$)6-chloro-7,8-dihydroxy-1-phenyl 2,3,4,5-tetra-hydro -lH-3benzazepine (SKF 81297), dopamine $D_1$ receptor agonist, produced diuresis by both Indirect action through central function and direct action being induced in kidney. This study was attempted in order to examine the diuresis mechanism of such SKF 81297 Diuretic action of SKF 81297 given into the vein or the carotid artery was not affected by renal denervation, whereas diuretic action of SKF 81297 administered into a renal artery was blocked completely by renal denervation, and then diuretic action of SKF 81297 injected into carotid artery was inhibited by SCH 23390, dopamine $D_1$ receptor antagonist, given into carotid artery. Above results suggest that indirect diuretic action of SKF 81297 elicites through central dopamine $D_1$ receptor and direct diuresis in kidney by influence of renal nerves.