Objectives : On an experimental basis, the effects of atopic dermatitis induced materials on the expression of cytokine genes in human monocytes (THP-1, U937) and mast cells were studied. This study was carried out to be considered a fundamental knowledge in the research on the good of oriental medicine. Methods : After culturing THP-1, U937, and HMC-1, with the three different concentrations of LPS ($1;{mu}g/ml$), DPE ($10;{mu}g/ml$), and DNCB ($1;{mu}g/ml$), atopic dermatitis induced materials were treated in the culture medium. To investigate cytokine genes expression patterns, with lysis buffer and separation reagent, total RNA was extracted from THP-1, U937, and HMC-1 at intervals of 0, 12, 24, and 48 hours. Both cytokine mRNA expression patterns by atopic dermatitis induced materials and change of cytokine genes expression patterns in relation to atopy by selenium were analyzed with RT-PCR. Also IL-4 and INF-$gamma$, which were secreted in the HMC-1, were analyzed using ELISA method. Results : 1. After treating THP-1 and U937 with LPS, DPE, and DNCB, there was no significant change in cytokine genes themselves, but various cytokines (IL-4, IL-6, IL-8, IL-13, IFN-$gamma$, IFN-a, MCP-1, B2-MG) were expressed. 2. In the case of HMC-1, the expressions of IL-6 and IL-8 were significantly increased in the analysis of mRNA expression by dust mite allergens in DPE. 3. As a result of ELISA method, it is certain that IL-4 and IFN-$gamma$ protein were secreted in the HMC-1 by DPE. 4. Selenium, an essential trace element, decreased the IL-10 and IL-13 expression in the HMC-1 by DPE. Conclusion : The results suggest that it is necessary to choose proper atopic dermatitis induced materials and suitable cultured cells in establishment of in vitro model of atopic dermatitis.