To obtain the risk assessment of hazardous materials in Rehmanniae Radix Preparata, the residual pesticides and heavy metals in samples on the Korea and China are surveyed. Group I ($BHC-{delta}$, $BHC-{eta}$, Fenitrothion, Penthoate, Endosulfan-${alpha}$, Dieldrin, Endosulfan-${eta}$ and Endosulfan-sulfate), Group II (BHC-${gamma}$, Aldrin, DDD, DDT-p,p Permethrin and Fenvalerate), Group III(BHC-${alpha}$, Chlorpyrifos, Tolyfluanid, Captan and DDT-o,p) and Group IV(Quintozene, Vinclozolin, DDE and Chlorfenapyr) could analysed on gas chromatography-ECD for evaluation of residual pesticides. Qualified detection concentration on the GC-ECD are $0.45 ng/g{sim}2.50 ng/g$. Group I, Group II, Group III and Group IV are not detected in Rehmanniae Radix Preparata on the Korea and China. Concentration of As, Cd and Pb in Rehmanniae Radix Preparata. on the Korea are 3.06%, 7.00% and 5.78% for Korea Food & Drug Administration(KFDA). Concentration of As, Cd and Pb in Rehmanniae Radix Preparata. on the China are 5.16%, 5.33% and 6.50% for Korea Food & Drug Administration(KFDA). The hazardous materials in Rehmanniae Radix Preparata on the Korea and China were verified the safety of the residual heavy metals and pesticides compare with Korea Food & Drug Administration (KFDA) advisory level.