131I-O-Iodohippurate renogram in 15 cases of epidemic hemorrhagic fever (E.H. fever) during oliguric, diuretic and convalescent phase were analysed quantitatively and qualitatively, namely by its configuration, Tmax T½ and renal index of Hirakawa. The results were as following:1) Changes on the renogram in E.H. fever showed simultaneous bilateral renal impairment. 2) The characteristic configurations of renogram in the oliguric phase were:① Moderately decreased absolute amplitude of initial spike. ② Continous rising second slope. ③ No appearance of terminal descent. Those were most likely to those of renogram in acute ureteral obstruction or acute dehydration state. 3) During the diuretic phase, the renogram showed the point of maximal amplitude, but the steepness of 2nd slope was markedly decreased. The appearance pf terminal descents was observed with unusually high amplitude despite of the tremendously large amount of urinary output during this phase. 4) In convalescence, the renogram were essentially normal in configuration, but the renal index of Hirakawa was not recovered until this phase. 5) Renogram in E.H. fever showed the characteristic patterns in each phase of its clinical course. 6) 131I-OIH-Renogram might be an useful method for the evaluation of renal function in E.H. fever during its course.