A set of brecciated ultramafic rocks in the Wajilitage area of Bachu, Xinjiang, was discussed in the paper. It has a wide variety of texture and composition and consists of three parts: xenoliths of ultramafic rock, porphyritic crystals (or xenocrtsys) and matrix. The xenoliths of ultramafic rock are mainly of clinopyroxenite and dunite with a few olivine pyroxenite, and they all belong to the magmatic crystallized complex. No mantle xenolith has been found. The porphyritic crystals are mainly composed of olivine and phlogopite. The matrix appears as emulsion with browngrey colour under microscope and is mixed of microcrystals (10~40 μm) of clinopyroxene, andradite, perovskite, magnetite (or titaniferous magnetite), serpentine, carbinite and a few sulphide. The xenocrysts include clinopyroxene, brown amphibole and apatite as well as titaniferous mafmatite. The brecciated ultramafic rocks in the study area belong to a part of kimberlite by means of several discriminant diagrams, but differ from some typical kimberlites of the world because of lower MgO and Mg# and higher TFe2O3 and CaO. These rocks havesteeply rightdipping REE distribution patterns, similar to that of typical kimberlite, but have lower (La/Yb)n ratios than that of typical kimberlite. The spider diagram of the brecciated ultramafic rocks is also similar to that of typical kimberlite but has higher abundance of incompatible elements, and stronger negative anomalies of K and Ti and negative anomalies of Rb,Zr, P, suggesting lower degree of mantle metasomatism. The brecciated ultramafic rock is not a typical kimberlite but may be called kimberlitic brecciated peridotite, because it is similar to typical kimberlite in the occurrence, texture, structure, mineral assemblage, geochemistry. But it differs from typical kimberlite in lacking the index minerals of kimberlite such as highCr chromite, pyrope and magnesoilmenite etc. Based in the studies on a limited number of samples, the authors consider that the kimberlitic brecciated peridotite in the Bachu area has no potentiality for diamond. There are still many brecciated ultramafic sills and dykes occurring in the Bachu area, which remain to be studied further.