[en] Radioprotective effects of Anchu-San and its constituents were studied in mice. Oral administration of Anchu-San, Grycyrrhizae Radix (GR) and Amomi Semen suppressed radiationinducing death. The differences within survival ratios of drug-administered groups to the control were under 0.02, 0.001 and 0.03, respectively, on 30-days after γ-irradiation (860 R). Other five drugs gave no effects on survivals. Time course changes in blood figures of GR-administered and control mice were assessed for 30-days after X-irradiation (550 R) by measuring erythrocyte, leukocyte and thrombocyte numbers. However, stimulation of hematopoietic function by GR-administration was not found. In case of the analysis of the effects of GR on survivals, other factors such as the stabilization of arterial wall by grycyrrhizin must be noted. (author)