Summary: The constitutive expression of nuclear-factor-κB (NF-κB) in human pigment epithelial (hRPE) cells cultivated in vitro and the possible changes when incubated with PDTC and IL-1β were investigated. The synchronized hRPE cells in vitro were divided into two groups. In non-PDTC group, hRPE cells were exposed respectively to IL-1βand NS (for detecting the constitutive expressions of NF-κB in hRPE cells); In PDTC group, PDTC-pretreated hRPE cells were exposed respectively to IL-1βand NS (for detecting the constitutive expression of NF-κB in PDTC-pretreated hRPE cells). The expression of NF-κB in hRPE cells in two groups was detected by immunofluorescence stain and flow cytometry. The results showed that the constitutive expression of NF-κB in hRPE cells in vitro was 8.05 %, and increased to 30.26 % by IL-1β. After PDTC pretreatment, the constitutive expression of NF-κB in hRPE cells was decreased to 3.74 %, and 3.66 % by IL-1βrespectively. It was concluded that the expressions of NF-κB in hRPE cells could be increased significantly by IL-1βand depressed effectively by PDTC. Also, PDTC could significantly inhibit the activation of NF-κB induced by IL-1β.