Background and Objectives : Allergic Contact Dermatitis is the disease affected by industrialization. The more industrialization advanced, the more materials that could induce the allergic contact dermatitis have been increased. Therefore in oriental medicine, various studies have been performed. The objective of this study is to investigate the effects of Naetakchunkeum-san on the Allergic Contact Dermatitis induced by 2,4-dinitro-chlorobezene(DNCB). Meterial and Methods : Twenty eight mice were divided into four groups ; normal, control, experimental group A and B. Control and experimental group were induced allergic contact dermatitis by DNCB. Experimental group A was orally administered the Naetakchunkeum-san and experimental group B was orally administered the prednisolone. In this study, ear thickness measurement, observation auricle microphotograph, Myeloperoxidase(MPO) activity measurement, Reverse transcription-polymerase chain reaction(RT-PCR) analysis of the mRNA level of $TNF-\alpha$, $IL-1\beta$, $INF-\gamma$ were performed on these four groups. In addition, the effect of Naetakchunkeum-san on cell viability and the effect of Naetakchunkeum-san on the compound 48/80-induced histamine release from HMC and RPMC were measured, Results : 1. In contact hypersensitivity assay, experimental group A and B showed decreased ear thickness compared with control group, 2. In experimental group A, pathological lesion of dermatitis were alleviated. In addition, the numbers of infiltrated cells were reduced, and cleft was not shown compared with control group, In experimental group B, similar results were shown. 3. There was a significant increase in MPO activity in control group compared with normal group, Experimental group A and B significantly inhibited the increase in MPO activity compared with control group. 4, The level of expression of $TNF-\alpha$, $IL-1\beta$, $INF-\gamma$ in experimental group A and B were significantly lower than those in control group. As the internal control, cyclophilin mRNA was also reverse-transcribed and amplified. 5, In MTT assay, there were no statistically significant differences in 100 ${\mu}g/ml$, 200 ${\mu}g/ml$, 500 ${\mu}g/ml$, 1000 ${\mu}g/ml$ Naetakchunkeum-san treated group from 0 ${\mu}g/ml$ Naetakchunkeum-san treated group as determined by the Tukey test. 6. Naetakchunkeum-san dose-dependently inhibited the compound 48/80-induced histamine release from both HMC and RPMC. Conclusions : According to above experiments, Naetakchunkeum-san may be applied to allergic contact dermatitis.