Abstract: Taking the Seashore Quartz Sand Ore at Wenchang Hainan province as a case, the Mineral Liberation analyzer (MLA), scanning electron microscope(SEM), and other analysis was used to study the mineralogical characteristics of seashore quartz sand ore in this paper. The result shows that the ore's SiO₂ content is 98.63%, and the content of quartz is 98.25%. the others mineral are rutile, zircon, clay mineral, and so on. The 75% of rutile and zircon in ore are crude and liberated, which can be separated. While other are very fine, and encapsulated by quartz, which can't be separated. The clay minerals are adhered in the surface of quartz, and can't be separated completely. Comprehensive Analysis shows that in seashore quartz sand ore, there are clay minerals adhered in the surface of quartz, which can't be separated completely. So it can't be used to make high purity quartz sand. And the content of fine rutile and other minerals are imparity in different ore. So it makes the quality of products from different ore imparity.