Abstract: Using mechanical dynamic triaxial test apparatus and electro-hydraulic dynamic triaxial test apparatus, liquefaction tests of a saturated standard sand were conducted in order to compare the effects of apparatus type, and sample size on dynamic strength. Two groups of test were performed concerning consolidated condition. One was under the condition of isotropic consolidation and the other under the condition of anisotropic consolidition.According to the test results, some points such as apparatus type, failure criteria and dynamic strength parameters of sand are discussed.