The location expansion of the red imported fire ant, Solenopsis invicta Buren,in a special ecology system were investigated and analyzed.The result showed the square area of the infestation was up to(226 hm~2) about 8 years after it was introduced to this area;Expansion distance were as follows: it spread to upper and lower reaches with the distance of(262) and(3 770 m) respectively.Active mounds densities were different among different types of habitat,with field bank>riverbank>roadside>village >riverbed. Average expansion speed of red imported fire ant was(187.9 m/year) in this area.