Objective : To investigate the effects of Radix Ophiopogon japonieus on atopic dermatitis, I prepared DNCB(2,4-dinitrochlorobenzen) induced atopic dermatitis NC/Nga mice and observed the mice by four ways; eye observation, the number of skin behavior times, histological changes of skin and cytokine(Total IgE, IL-4, $IFN-{gamma}$). Methods : After prepare Radix Ophiopogon japonicus extract, DNCB induced atopic dermatitis NC/Nga mice were divided into three groups. The first is Control group which was intact group. The second is Medication group which was orally medicated Radix Ophiopogon japonicus extract one time a day for consecutive 5 days. The third group is Application group which was applied Radix Ophiopogon japonicus extract externally one time a day for consecutive 5 days. After that, the effect of Radix Ophiopogon japonicus on atopic dermatitis was observed. Statistical analysis was performed by using Kmskal-Wallis test and statistical significance was set at less than 5%. Results : 1. Radix Ophiopogon japonicus showed some in both Medication group and Application At observation of skin morphologic change, effects to prevent erythema reaction on skin group. 2. At the number of scratching behavior times, Radix Ophiopogon japonicus showed an effect to decrease scratching behavior times, but there was no statistical significance among three groups. 3. At skin tissue H-E stain, Radix Ophiopogon japonicus showed an effect to prevent skin epidermal tissue damages and also showed that it could keep the skin healthy in both Medication group and Application group. Especially in Application group, the skin of mouse showed almost normal recovery. 4. At cytokines, there was no statistical significance among three groups in IgE and IL-4. But Radix Ophiopogon japonicus showed an significant effect to suppress $IFN-{gamma}$ in both Medication group and Application group. There was no significant difference between two groups. Conclusion : Radix Ophiopogon japonicus has some effects on atopic dermatitis in both internal medication and external application.