The characteristics of soil liquesfaction were investigated using the H/V rations of microtermors in the Yuan-Lin area. Liquefaction at Luen-Ya-Li, Yuan-Lin in central Taiwan was clearly observed with serious sand boils bringing about massive damages during the Chi-Chi earthquake. Based on the H/V ratios calculated from microtremor measurements at 42 points distributed in this area, the predominant frequencies appeared between 0.8-0.9 Hz for the liquefied area, with higher relative amplification factors compared to other areas. In the study, the ground vulnerability index (K_g) values (Nakamura 1996) in the liquefied areas were higher than those in the neighboring areas without liquefaction. This study shows supporting evidence for the first time that the H/V ratios of microtremors can be a good alternative indicator for an area's potential for liquefaction.