Abstract: With simulation seismic loads in a laboratory, the vibration table experiment of the liquefied soil improved by soil-cement piles are carried on. a variety of pore water pressure of non-improved and improved soil under the same buried depths and different dry density is utilized to discuss liquefaction effects of soil-cement pile at different dry density. It is revealed that the drainage effects of soil-cement piles is not evident and the liquefaction effects of is not considerable. It should be carefully chosen in engineering applications.