Objective To investigate the mechanism of TNF-α on regulating the blood-labyrinth barrier permeability of cochlea of guinea pig.  Methods The stria vascularis was acquired from guinea pigs and the endothelial cells were cultured of with purified to establish the models of the blood-labyrinth barrier according to our previous researches. The models were treated with TNF-α (0.05

0.1

0.2 ng/ml) for 30

60

90 min or with serum-free DMEM as control. Then their permeability was measured by Evens blue technique. Results TNF-α increases Evans blue transfer across endothelial cell monolayer (P0.01). The filtration rate of Evans blue across the endothelial cell monolayer increased positively with prolonged treatment time or the increasing TNF-α concentration. Conclusion TNF-α enhances the permeability of blood-labyrinth barrier in guinea pig.