Abstract: The kimberlite from Shandong Mengy mainly consists of alteration minerals. X-ray powder diffraction results showed that the barren-kimberlite consists of calcite, dolomite, quartz, calzirtite with dolomite and calzirtite as the signature minerals, the lean-kimberlite consists of serpentine, calcite, grossular, magnetite and phlogopite with grossular as the signature mineral, the rich-kimberlite consists of serpentine, calcite, chlorite, apatite, magnetite and phlogopite with chlorite and apatite as the signature minerals. The research results indicate that X-ray powder diffraction is a powerful tool for identifying kimberlite alteration mineral composition, studying on the relationship between component change of alteration minerals and ore potentiality of kimberlite, and assessing barren-kimberlite, lean-kimberlite and bonanza-kimberlite based on the signature minerals.