Objective To study the regulation effect of nuclear factors-κB activator 1（NF-κB activator 1,Act1）on high glucose induced inflammatory response and extracellular matrix expression in renal tubular epithelial cells．Methods Renal tubular epithelial cells MK2 were cultured and control group and high glucose group were set．The mRNA and protein expression of Act1 were detected after treatment for 12,24,48 and 72 hours．MK2 were divided into si-NC group（transfected with NC siRNA in 5.5 mmol/L glucose medium）,si-NC+high glucose group（transfected with NC siRNA in 30 mmol/L glucose medium）and si-Act1+high glucose group（transfected with Act1 siRNA in 30 mmol/L glucose medium）．The mRNA and protein expression of Act1,E-cadherin,N-cadherin,type I collagen（Col-I）,and type III collagen（Col-III）and the contents of tumor necrosis factor-α（TNF-α）,interleukin-1β（IL-1β）,interferon-γ（IFN-γ）in culture medium were detected．Results The mRNA and protein expression levels of Act1 in cells of high glucose group were higher than those of control group at 12 h,24 h,48 h and 72 h（P<0.05）．The mRNA and protein expression levels of Act1,N-cadherin,CoL-I,Col-III in cells and the contents of TNF-α,IL-1β,IFN-γ in culture medium of si-NC+high glucose group were higher than those of si-NC group,the mRNA and protein expression levels of E-cadherin in cells were lower than those of si-NC group at 48 h（P<0.05）．The mRNA and protein expression levels of Act1,N-cadherin,CoL-I,Col-III in cells and the contents of TNF-α,IL-1β,IFN-γ in culture medium of si-Act1+high glucose group were lower than those of si-NC+high glucose group,the mRNA and protein expression levels of E-cadherin in cells were higher than those of si-NC+high glucose group at 48 h（P<0.05）．Conclusions The increased expression of Act1 promotes the activation of inflammatory response and the increase of extracellular matrix in renal tubular epithelial cells induced by high glucose．