This study is concerning to identify the hygienic problems occurring in processing, storage, and distribution of Rehmanniae radix crude, and to investigate the possibility of application of safe and hygienic ${gamma}-irradiation$ techniques. The results are as follows. To compare the contents of catapol, index compound of Rehmanniae Radix crude, between before and after ${gamma}-irradiated$,0,2.5,5,7.5,10,12.5,15,20, and 30 kGy of ${gamma}-irradiation$ was applied to standard catapol and Rehmanniae radix crude. The contents of catapol in standard material and Rehmanniae radix crude were decreased with the increase of ${gamma}-irradiation$ level. However, active components of Rehmanniae Radix crude were not changed with ${gamma}-irradiation$. These results indicate that active components of Rehmanniae Radix crude were preserved after ${gamma}-irradiation$ and those of Rehmanniae Radix crude did not showed significant change after irradiation of ${gamma}-ray$ up to 20 kGy.