The current study was undertaken to select the crude drug showing life prolonging effect on the starved rats(Sprague-Dawley) and elucidate the reaction mechanism there of. As distilled water extracts prepared from twenty kinds of natural drugs were administered orally to female starved rats, Bupleuri Radix demonstrated the most prominent effect with 34.6% increment in the survival time. To investigate underlying mechanism of life prolonging effect of Bupleuri Radix, the concentrations of adrenocorticosteroids(corticsterone, testosterone and aldosterone) and enzyme activities of superoxide dismutase(SOD), glutamate oxaloacetate transaminase(GOT), glutamate pyrurate transaminase(GPT) were assayed in the serums of rats starved for, 2, 4 and 6 days respectively. The results manifested much elevated values of corticosterone, aldosterone(2 days) and rather decreasing tendency afterwards, specially in the late periods of starvation(6 days). With respect to such a considerable changes according to starvation periods, Bupleur Radix restored these values much near to normal suggesting that Buplerum Radix may play a life prolonging action during starvation probably through reinforcing the homeostatic properties of corticosteroids and some enzyme activities.