|Abstract:There are two types of diamond ores with industrial value in western Shandong Province, including primary diamond ore and alluvial diamond ore. Diamond-bearing mother rocks of primary diamond ores mainly are kimberlite and lamprophyre. Diamond-bearing mother rocks of alluvial diamond ores are conglomerate and sandstone, and they occur in Quaternary Xiaobuling Formation and Yuquan Formation. Cambrian Liguan Formation, Carboniferous Benxi Formation, Jurassic Santai Formation, Paleogene Guanzhuang group and Neogene Baiyan Formation are also the diamond-bearing strata, but they can not meet the industrial utilization requirement. Compared to the diamonds contained in these reservoirs, the diamond particle size in Mengyin and Feixian of Benxi Formation is the largest, the diamond content in Pingyi-Sishui area of Baiyan Formation is the richest, the proportion of complete crystal shape in Linyi Jinqueshan of Santai Formation is the highest, and the erosion and roundness in Zaozhuang Shangnihe and Sishui Xuezhuang area of Liguan Formation are the most serious. Different strata and types of diamond indicate different source region, forming age and tectonic backgrounds. Lithofacies paleogeography analysis shows that the diamonds of Liguan Formation are originate from its southwest of ultramafic rocks in the Early Precambrian crystal basement of the Mashan-Sihaishan region. These ultramafic rocks were formed in the Neoarchean, and then the Early Precambrian crystal basement uplift in the Late Proterozoic, and the ultramafic rocks underwent thereafter denudation, at last a small amount of diamond was deposited in the Liguan group conglomerates at the bottom of the Cambrian. The distribution and characteristics of diamonds in Benxi and Santai Formation indicate that the source region is Mengyin kimberlite. The kimberlite in Mengyin was formed in the Early-Middle Ordovician. After the formation of kimberlite, the Caledonian and Indosinian Movement-the Early Yanshan Movement resulted in the uplift of Culaishan-Mengshan district. Afterwards, the kimberlites were lifted to the surface and denuded, and the diamonds were deposited in conglomerate of Benxi and Santai Formation respectively. The distribution and characteristics of diamonds in Guanzhuang Formation, Baiyan Formation, Xiaobuling Formation and Yuquan Formation indicate that they also mainly come from Mengyin kimberlites. The Cenozoic Culaishan-Mengshan in the north of western Shandong Province is still in a strong uplift state, which results in the distribution of Baiyan Formation, Xiaobuling Formation and Yuquan Formation diamond enrichment areas in the south of western Shandong Province. The geochemical characteristics of the diamond source region in different ages indicate the chemical evolution of mantle. North China block from Archean to Paleoproterozoic mantle source region of εNd(t) value is from +0.5 to +4 indicates that the upper mantle is in a weak deficit condition. The εNd(t) value of kimberlite in the western Shandong Province varied from -4.78 to +2.76, suggesting that the Paleozoic mantle was in a state of weak enrichment. The εNd(t) value of Mesozoic mafic rocks in the western Shandong Province varied from -9.2 to +21.21, suggesting that the Mesozoic mantle was in a state of strongly enrichment. Diamond deposits in kimberlite pipes were derived from early Paleozoic weak enrichment mantle in the western Shandong Province.