Abstract: The red coral is one of the important organic gemstones.In recent years, the microstructure characteristics of the red corals are studied by using the modern microanalysis methods from the crystallography, biology and gemmology.Firstly, the surface and internal microstructure characteristics of the skeleton of the Coralliidae family are preliminarily analysed and summarized.The different varieties in Coralliidae family have the different structure characteristics.The results about the organic matrix mesh in the red coral obviously show that the morphology is controlled by the interaction between the calcite and organism.Finally, the study directions on the structure characteristics of the skeleton of Coralliidae family will be interspecific differences in the structure characteristics, environmentology, biomineralization controlled by organism and so on.