In this study, the difference in triaxial shear property of Liquefied Stabilized Soil (LSS) mixed with fiber material cured in laboratory and at field was investigated. A series of Consolidated-Undrained triaxial compression tests under the conditions at constant strain rate, constant deviator stress (partial creep test), and changed strain rate during monotonic loading have been carried out for both specimens of LSS mixed with fiber material amount of 0 and 20 kg/m 3 prepared by trimming LSS retrieved from a model ground by block sampling and cured in laboratory at curing time of 28 and 56 days, respectively. Based on the test results, it was found that the maximum deviator stress, q max in q~ curve of LSS mixed with fiber material cured at field tend to be larger than that cured in laboratory, and the brittle property of LSS after the peak in q~ε curve has been improved to ductile property by the addition of fiber material even in field.