The results of mineralogical and spectroscopic studies on 115 diamond samples from the Tancheng placer of Shandong Province show that the particle sizes are concentrated in the range of 1. 0~4. 0 mm. The crystal morphology is mainly rhombic dodecahedron, followed by octahedron and rhombus dodecahedron aggregation; of these the octahedron form is least abundant. In addition to the development of primary morphology, such as the inverted triangle pit, the plastic deformation slip line, the melt erosion ditch, growth hill, the growth ladder, imbricate erosion image, the dropwise hill and the halo line, a small part of the crystal surface has secondary morphology and green spots. Most of the diamonds have clear edges and low roundness. In this study, the half height width data and inclusion Raman spectrum of the Raman characteristic peak of the Tancheng diamonds were measured for the first time. The test results show that the diamond crystallinity of the Tancheng placer is distinctive, indicating the complexity of the geological growth conditions and environment. The diamond inclusions include olivine, chalcopyrite, goethite and graphite minerals, of which olivine inclusions account for a relatively high proportion, indicating that the type of diamond inclusions in the Tancheng is dominated by peridotite. The test results are consistent with the conclusion that most of the lithospheric mantle under the old craton in the east of North China is composed of peridotite. A preliminary discussion on the source of diamond placer is based on the comparison of the characteristics of the Tancheng and the Mengyin diamonds. The study provides new evidence for the formation and evolution of diamond and its inclusions.