Abstract: This paper reports the experimental results on the effects of interleukin-1 (IL-1), tumor necrosis factor-α (TNF-α) and granulocyte/macrophage colony-stimulating factor (GMCSF) on the expression of CDla surface antigen of human epidermal Langerhans cells (LC) cultured in vitro. We discovered or iat IL-1 and TNF-α migkxt promote or maintain the expression of CDla surface antigen of LCGM-CSF might suppress the function of LC expressing CDla surface antigen.This experiment alsa proved that in the absence of any cytokine the LC cultured in vitro could not be kept alive easily. Because CDla is a specific surface antigen of LC it is important For the function of LC. It had better establish LC model maintaining the exprestion of CDla for further study on the function of CDla. and the Effecrtc and mechanism of the above three cytokines on the expression of CDla surface antigen of LC.