This paper is the result of geological survey engineering. [Objective] Dolostone is not only good reservoir, but also a type of significant non-metallic ore. Dolostone is an important raw material for producing magnesium. Our country has the largest reserve and producing of magnesium resource in the world. Therefore, magnesium resource is also an important key mineral resource. To study the characteristics, origin, distribution and exploitation value of dolomite is beneficial to the security of national key mineral resources. [Methods] By reviewing the researches about dolomite at home and abroad, the paper summarizes the characteristics, types, distribution and utilization value of dolomite systematically. [Results and conclusions] Dolostone is mainly composed of dolomite, which belongs to trigonal system with rhombohedral crystal shape. According to its original types, the dolostone can be classified into primary dolostone, diagenetic dolostone and epigenetic dolomite. The dolomite is mainly product of replacement with precursor calcite structures. The dolostone is almost distributed in all the strata in geological time, the majority of which is buried deeply. Only a small part of it is exposed at outcrop and could be exploited as dolomite ore. The dolostone is widely distributed in Proterozoic and Paleozoic, and regionally distributed in Mesozoic and Cenozoic. The dolostone can be used as metallurgical solvent (MgO≥15%) and refractory material (MgO≥18%), to extract metal magnesium (MgO≥19%), to manufacture cement (MgO＞18%) and building materials, to produce reducing salt in pharmaceuticals industry, to be used as fertilizer (MgO＞20%) and feed in agriculture, etc., which is a kind of widely used non-metallic minerals. Dolomite ore resources are abundant in China，which is also an important raw material for magnesium metallurgy. The reserves of metallurgical dolomite mineral resources are 1.875 billion tons. China is the world's largest reserves of magnesium resources, taking more than 20% of the world's total reserves. It is also the world's number one producer of magnesium. In 2022, the national raw magnesium production was 893,600 tons and exports exceeded 500,000 tons in 2022. Therefore, magnesium resources are also important key mineral resources. The rapid development of magnesium industry will also increase the demand for dolomite mineral resources.