This study sought to elucidate whether Rac1 mediates the migration of endothelial cell induced by IL-8. The Transwell chamber motility assay was conducted to disclose the effect of different matrigel dilution and different time of IL-8 treatment on the migration of endothelial cells. The mRNA of Rac1 was detected by RT-PCR. The results demonstrated that when the concentration of Matrigel was 1:2, there is significant difference on the amounts of migration cells than that of the concentration of 1:3 or 1:8; When the dilution of Matrigel was 1:4, 1:5 or 1:6, there is no significant difference on the amounts of migration cells than that of other dilution groups. So we choose the Matrigel concentration as 1:4. With the increase of IL-8 stimulation time, the cells which migrated from upper reservoirs to lower reservoirs progressively increased. After six hours stimulation by IL-8, the expression of Rac1 mRNA in migrated cells was increased, compared with that of other groups. The results suggest that Rac1 may mediate the migration of endothelial cells induced by IL-8. It can also be the foundation for further investigation on the role of Rac1 in the migration of endothelial cells induced by IL-8.