The soil reinforcement is expected to become an effective protection method in case that the soil liquefaction is anticipated to occur for the existing fasility. In this paper, the authors have investigated the effectiveness and reinforcing method by model test for various pattern of reinforcement. As a result, it has been became clear that the large friction and fixed head of reinforcement bars are very effective for prevention of soil liquefaction. Based upon the experimental results, they have also studied on the mechanism of reinforcement against liquefaction and suggested its evaluation.