The aim of this study was to investigate the expression of Krupple-like factor 4 (KLF-4) in human umbilical vein endothelial cells (HUVEC) under stimulating of cytokines IL-1beta and TNF-alpha. The HUVEC were isolated, cultured and exposed to IL-1beta, TNF-alpha for 2 and 4 hours, the expression level of KLF-4 mRNA was detected by real-time PCR, the expression level of KLF-4 protein was measured by Western blot, the location of KLF-4 in HUVEC was determined by confocal laser microscopy. The results showed that the KLF-4 mRNA lowly expressed in normal HUVEC, but highly expressed in HUVEC after stimulation with IL-1beta and TNF-alpha; furthermore the expressions of KLF-4 mRNA and protein were enhanced along with prolonging of time. Confocal laser microscopy showed that the expression of KLF-4 was enhanced in nucleus and plasma of HUVEC after stimulating with IL-1beta. It is concluded that the expression of KLF-4 increases under IL-1beta and TNF-alpha stimulation which may participate in regulation of endothelial activity.