There exist four layers of volcanic rocks in Sinian and Cambrian strata of Kuruktag area, Xinjiang. They occur in Early Sinian Beiyixi Formation, Late Sinian Zhamoketi Formation and Shuiquan Formation as well as Early Cambrian Xishanbulake Formation respectively. Volcanic rocks of Xishanbulake Formation and Shuiquan Formation are of alkali basalt series, those of Zhamoketi Formation are of alkali basalt series and tholeiite series, and those of Beiyixi Formation are obviously characterized by bimodal assemblage and mostly belong to alkali volcanic rocks. Their multi_element distribution patterns show continental tumescence characteristics of intraplate basalt. Fractional crystallization of plagioclase led to the existence of negative Eu_anomalies in some volcanic rocks, while the cumulation of olivine resulted in the high MgO and low SiO 2 content of some volcanic rocks. The SiO 2 saturability of volcanic rocks of Xishanbulake Formation and Shuiquan Formation is lower than that of tholeiite of Zhamoketi Formation. Correspondingly, the abundances of incompatible elements in the first two formations is higher than those in the last formation, and the differences can be attributed to the different degrees of partial melting. The intense fractionation of REE and the obvious depletion of HREE suggest that these volcanic rocks were derived from garnet lherzolite of the mantle in the continental lithosphere. The Ba/Nb, La/Nb, Ba/La, Ba/Th and Rb/Nb ratios demonstrate that these volcanic rocks were exclusively derived from the enriched mantle, mainly the EMI type mantle.