hCTLA4-Ig,which is capable of inhibiting T cell activation and rendering T cell to be anergy by blocking co-stimulatory signal pathway, is recognized as a potential therapeutic molecule to extend the survival of skin graft in burn medicine. To investigate whether the survival of skin graft can be further extended by skin-specific expression of hCTLA4-Ig, a skin-specific expression vector was constructed by pacing the encoding sequence of hCTLA4-Ig under the drive of K14 promoter, and a transgenic mouse line was established with the vector. RT-PCR and Northern blot assay indicated that hCTLA4-Ig was skin-specifically expressed in transgenic mice at a rather high level. Compared with the expression of GAPDH, the expression of hCTLA4-Ig remained constant through generations and over lifetime. The results of this paper indicated that a transgenic mouse line skin-specifically and constitutively expressing hCTLA4-Ig had been established.