The objectives of the study are to survey the effects of different concentrations of collagen, ceramides, N-acetyl glucosamine (NAG), or their mixture on the proliferation of keratinocytes, fibroblasts and on the secretion of collagen and/or the expression of mRNA of type I collagen. The optimal concentrations that facilitated the proliferation of fibroblasts were 49, 2.0, and 24.4 μg/mL, respectively for collagen, ceramides, and NAG. The proliferation percentages were 191%, 170%, and 223%, respectively at the same order in compare to the control. The concentration of the mixture containing 6.1, 0.12 and 6.1 μg/mL, respectively of collagen, ceramides, and NAG facilitated the proliferation of fibroblasts. The optimal concentrations that had highest keratinocytes proliferation were 0.76, 0.001, and 0.76 μg/mL, respectively for collagen, ceramides, and NAG. The proliferation percentages were 242%, 203% and 230%, respectively at the same order in compare to the control. The optimal concentration that effects the highest keratinocytes proliferation by the mixture were 0.38, 0.008 and 0.38 μg/mL for collagen, ceramides and NAG, respectively. The concentrations for fibroblasts to express higher amount of type I collagen mRNA were 6.1, 0.49, and 6.1 μg/mL, respectively for collagen, ceramides, and NAG. The expression levels of type I collagen mRNA were 152%, 160% and 220%, respectively at the same order in compare to the control. However, the expressions of type I collagen mRNA were 180% in compare to the control at the concentration of mixture containing 0.76, 0.015 and 0.76 μg/mL, respectively of collagen, ceramides, and NAG.