Gami-Honghwa-Tang (KH-19), a herbal prescription for reducing the side effect of radiotherapy, is composed of eight crude herbs such as Rehmanniae Radix Preparata, Angelicae Gigantis Radix, Cnidii Rhizoma, Paeoniae Radix, Corni Fructus, Moutan Cortex Radicis, Lycii Fructus, Carthami Flos, and Glycyrrhizae Radix. In this study, marker substances in KH-19 were analyzed by high performance liquid chromatography-diode array detector (HPLC-DAD) and safety evaluation of standardized KH-19 was evaluated by good laboratory practices (GLP) guideline of Korea Food and Drug Administration. HPLC-DAD was employed to determine the quantities and the qualities of several marker substances such as 5-hydroxymethyl-2-furaldehyde (5-HMF), paeonol, loganin, paeoniflorin, glycyrrhizin, and decursin in the KH-19. In acute oral toxicity study on rat, transient inhibition of body weight was shown, but change in general symptom was not detected. No dead animal was observed up to 5,000 mg/kg in both male and female animals. In acute oral toxicity study on Beagle dog, transient vomiting, diarrhea, anorexia, and body weight reduction were observed, However, no dead animal was observed up to 2,000 mg/kg in both male and female animals.