Background Generally speaking, undifferentiated keratinocytes may synthesize a larger amount of IL-α and its production is decreased as cells complete differentiation gradually. Ultraviolet B (UVB) light can signigicantly stimulate the production and release of some cytokines. In this study we investigated the influence of UVB irradiation on IL-1α and adenosine triphosphoric (ATP) mRNA expressions in the human keratinocyte (KC) of original squamous cell carcinoma line (SCC 12F cells).Methods The cultured SCC 12F cells were irradiated with 30 mJ/cm 2 of UVB. Northern blot was employed to analyze the expression of IL-1α and ATP mRNA. Results There was a constitutive expression of IL-1α mRNA in SCC 12F cells. The expression increased in culturing time in regular KC medium and reached the highest expression at 120 hours. The expression level of IL-1α was up-regulated with two peaks at 6 hours and 72 hours, respectively after UVB irradiation. In comparison with IL-1α mRNA expression, ATP mRNA was down-regulated, with similar biphasic peaks, compared with the sham irradiated group. Conclusions SCC12F cells may express IL-1α mRNA constitutively. After UVB irradiation, the mRNA expression of IL-1α and ATP will show opposite effect because of inflammation/immunity and energy consumption mechanisms. Background Generally speaking, undifferentiated keratinocytes may synthesize a larger amount of IL-α and its production is decreased as cells complete differentiation gradually. of UVB irradiation on IL-1α and adenosine triphosphoric (ATP) mRNA expressions in the human keratinocyte (KC) of the original squamous cell carcinoma line (SCC 12F cells). Methods The cultured SCC 12F cells were irradiated with 30 mJ / cm 2 of UVB . Northern blot was employed to analyze the expression of IL-1α and ATP mRNA. Results There was a constitutive expression of IL-1α mRNA in SCC 12F cells. The expression increased in culturing time in regular KC medium and reached the highest expression at 120 hours. The expression level of IL-1α was up-regulated with two peaks at 6 hours and 72 hours respectively after UVB irradiation. Conclusions SCC12F cells may express IL-1α mRNA constitutively. After UVB irradiation, the mRNA expression of IL-1α and ATP will show the opposite effect due to of inflammation / immunity and energy consumption mechanisms.