Systematic studies on the main mineralogy of the diatreme breccias in the Bachu, Xinjiang, the results show that the rocks consist of two parts: xenoliths of ultramafic rock and cements. In the cements, the chiefly minerals are clinopyroxene, olivine, plagioclase and amphibole. They are both from the crystallization of the Kimberlitic magma and the xenocrysts which are the same source of the xenoliths of ultramafic rock. In the cements, the latter phenocrysts have higher Mg# than the previous phenocrysts and Clinopyroxene and amphibole develop the reverse zoning, which indicating that the magma has sufferd the magma mixing during its evolution. This study also shows that there are many mineralogy differences between the xenoliths of ultramafic rock and the Wajilitage layered complex, so we can say that they are no causal relationship between the two. On the craton age, the thickness of the lithosphere, rocks exposed position and the depth of the magma source, the Bachu kimberlite is different from the kimberlite of the eastern China, which constitutes a negative factor for the deposit.