It has been well known that beta-adrenoceptor is responsible for the renin release stimulatory and alpha-adrenoceptor may be inhibitory. It has been observed accidently that alpha-adrenergic agonist can inhibit renin release by just changing the medium temperature in Vitro experiment in this laboratory. A series of experiments were performed to clarify this interesting phenomena in Vitro experiment. Rat renal slices were incubated in PSS medium under gas phase at 37℃. The following results were observed. 1) Isoproterenol and norepinephrine resulted in renin release stimulatory in dose-dependent by the concentrations of 10^-9 to 10^-5 M/L at 37℃. 2) Norepinephrine resulted in renin release inhibitory in dose dependent by the concentrations of 10^-7 to 10^-5 M/L, and almost no effect by isoproterenol 10^-6 M/L at 20℃. 3) Phenoxybenzamine pretreatment at 37℃ accentuated isoproterenol stimulatory effect at 37℃. 4) Phenoxybenzamine pretreatment at 20℃ attenuated isoproterenol stimulatory effect at 37℃. These data suggest that the renal adrenoceptor(s) related to renin release maybe a single entity, and can be interconverted different forms in certain conditions.