The purpose of this paper is to demonstrate the effectiveness of micro-bubble water injection method against soil liquefaction based on the result of seismic vibration test using large scale flexible shaking box. It is well known that soil resistance to liquefaction increases as the degree of saturation of the soil decreases, but the practical method to decrease the saturation of the soil has not been invented. The authors solved this problem by new method of injecting water containing micro-air bubbles into the ground. The method has an advantage which not only simple and cost-effective but also friendly to environment. We examined two cases, which are micro-bubble water injected sand ground and degassed water injected one, to compare the behavior of anti-liquefaction in the large scale test ground soil. As the result, it was observed that liquefaction did not occur even at maximum acceleration level of 200Gal under the condition of lowered saturation to 80% with N-value of around 7, which is loose or fragile ground. In addition, the results also could be suggested that the possibility of brand new method of “seismic avoid ground” with hybrid layered ground of air injected soil around housing foundations and liquefaction soil under the ground
