Abstract: Objective To study the mechanism of dermal fibroblasts as feeder layer to support the growth of human keratinocytes. Methods Human dermis fibroblasts were isolated and cultured and then treated with mitomycin-C and the expression of type Ⅰand type Ⅲ precollagen mRNA and relevant protein in feeder layer were examined by RT-PCR and Immunohistochemistry. KCs were cultured both on FB and NIH3T3 feed layer as control， the adhering numbers and the time of fusion were observed. Results RT-PCR revealed an increase of type Ⅰprecollagen mRNA in FB feeder layer compared with that of normal fibroblasts （P＜0.05）and no change was seen in type Ⅲ precollagen. Positive stains of collagen type Ⅰ and Ⅲ were shown in the FB feeder layer and those KCs grew and differentiated well on the FB feeder layer seeded at appropriate densities. There was no statistical difference in the adhering numbers and the time of fusion in two different culture feeder layer. Conclusions Human dermal fibroblasts as the feeder layer could secrete collagen type Ⅰ and Ⅲ which will contribute to multi-layered sheets of cultured keratinocytes.