Abstract: OBJECTIVE To study the morphological characteristics,microstructure and trace element contents of calcite from 3 different areas in southwest China and to provide experimental basis for the medicinal use of calcitum.METHODS The microstructures and trace element contents of 15 calcite from 3 different producing areas in Zimudang (Zhenfeng County,Guizhou Province),Badu (Tianlin County,Guangxi Province) and Zhesang (Funing County,Yunnan Province) area were studied by using microscope and inductively coupled plasma mass spectrometry (ICP-MS).RESULTS In the Zimudang area,calcite was often associated with realgar.The calcite was milky white and dark gray,and the calcite was vein-like and massive.The content of rare earth elements in calcite was significantly lower than that in the other two places,and the calcite was rich in rare earth elements,and the content of As,Zr and Sb elements in calcite were significantly higher than those in the other two places.The calcite in Badu area was mainly milky white massive and veined,and the calcite particle size was large,and visible rhombohedral stripes could be seen under the microscope.The rare earth elements in Badu calcite were uniform,but Eu element were abnormally enriched.The contents of Sc,Y and Ba in Badu area were significantly higher than those in other areas.The calcite in Zhesang area was mainly milky white with coarse veins,single mineral assemblage,small particle size and serrate contact between particles under the microscope.The calcite in Zhesang area was rich in heavy rare earth elements and had a wide range of Sc elements.The content of Sc elements in the calcite in Zhesang area was significantly higher than that in other places,with the maximum content of 18.4 μg·g^–1.CONCLUSION The morphology,microstructure and contents of trace elements of calcite in different regions are obviously different.When calcitum raw ore is used as medicinal materials,attention should be paid to its processing to eliminate the symbiotic impurities.