In order to evaluate water-insoluble chemicals using the skin model which is more similar to real skin and detectable interaction among three kind cells, we established a test method which is a three-dimensional human skin model consisting of normal fibroblasts, normal keratinocytes and normal dendritic cells utilizing a collagen vitrigel membrane (VG-KDF-Skin). Nine sensitizers and five non-sensitizers were then examined. After 24 hr, the amount of IL-1a and IL-4 release was measured, and then positive/negative outcomes were evaluated (VG-KDF-Skin method). The accuracy, sensitivity and specificity of positive/negative outcomes of the VG-KDF-Skin method, whose indicator is IL-4 release vs. local lymph node assay (LLNA), were 93%, 89% and 100%, respectively. The accuracy, sensitivity and specificity of the VG-KDF-Skin method, whose indicator is IL-1a release vs. LLNA, were 50%, 56% and 40%, respectively. In order to study the possibility of applying an established test method to cosmetic products such as milky lotion and cream, two model cosmetic samples containing a typical skin sensitizer [2,4-dinitrochlorobenzene (DNCB)] were made and IL-4 release evaluated. Significant IL-4 release was induced. These results suggest that it is possible the VG-KDF-Skin-method using IL-4 as an indicator for skin sensitization potential would be useful for evaluating the skin sensitization potential of chemicals and cosmetic products.