Abstract: In situ test indices of liquefied sands in 2003 Bachu earthquake, Xinjiang, China, were significantly larger, showing notable uniqueness compared to worldwide liquefaction case histories. Typical liquefied sands from Bachu earthquake and 1976 Tangshan earthquake were retrieved, mineral compositions and particle morphologies were analyzed, and dynamic triaxial tests were carried out for two kinds of sands with relative density of 30%, 50%, and 70% respectively. Tangshan sand is composed of 96.6% quartz and 3.4% limonite, while Bachu sand consists of 55.8% quartz, 17.3% calcite, and 26.9% vanadium titanium magnetite. Dynamic triaxial test results show that Bachu sand exhibits higher liquefaction resistance compared to Tangshan sand, slower development and larger fluctuation of pore pressure, and shear dilatancy arises after initial liquefaction, with relatively high residual strength and limited deformation progression. These characteristics becomes more prominent for Bachu sand under smaller dynamic stress. Based on evaluation results of liquefaction potential obtained from standard penetration tests, especially the misjudgment of all liquefaction sites in seismic intensity VII zone, liquefaction characteristics and mechanism of Bachu earthquake are highlighted. The magnitude of Bachu earthquake was relatively small, while the strength of Bachu sands was relatively high. The combined effect of external forces and internal causes led to a large amount of water spraying but a small amount of sand ejection during earthquake-induced liquefaction. After earthquake, Sand skeleton was damaged slightly, while pore water was discharged, resulting in a significant increase in sand density. Subsequent field test results show that mechanical indices were obviously larger, leading to a significantly misleading results of liquefaction discrimination.