SKP-450 which is $K^{+}$ channel opener, When given into duodenum, exhibited the decline of urine flow accompanied with the decrease of glomerular filtration rates (GFR), renal plasma flow (RPF), N $a^{+}$ and $K^{+}$ excreated in the urine ( $E_{Na}$ , $E_{K}$) and the increase of $K^{+}$N $a^{+}$ratios, and then appeared the significant fall of mean arterial pressure (MAP) and unchanged of reabsorption rates of N $a^{+}$, $K^{+}$ in renal tubules ( $R_{Na}$ , $R_{K}$). SKP- 450 injected into the vein elicited the decline of urine flow along with the reduction of $E_{Na}$ , $E_{K}$, and the increase of $R_{Na}$ , $R_{K}$ and $K^{+}$M $a^{+}$ ratios. SKP-450 administered into a renal artery produced diuretic action along with the increase of $E_{Na}$ , $E_{K}$ and the decrease of $R_{Na}$ , $R_{K}$ in experimental kidney, whereas produced the same aspect to intravenous SKP-450 in the control kidney. Above results suggest that SKP-450 possess both diuretic action in the kidney and central antidiuretic action in dog.tic action in dog.tion in dog.