Abstract: Carbonic anhydrase（CA）is an enzyme that reaction between carbon dioxide and water to produce carbonic acid. To investigate the function of CA gene family in the calcification process of Capitulum mitella, this study identified members of the CmCA gene family using bioinformatics methods, and analyzed their physicochemical properties, subcellular localization, secondary and tertiary structure, conserved motifs, chromosomal localization, transmembrane structure prediction and evolutionary relationships, and combined with transcriptome analysis of the expression pattern of CmCA in different developmental stages. The findings indicated that 10 CA gene family members were identified in the C.mitella genome, which were distributed on six different chromosomes. Physicochemical property analyses showed that the number of amino acids ranged from 108 to 318, with molecular weights between 12.10 kDa and 36.22 kDa and isoelectric points ranging from 5.09 to 10.68, and all of them were hydrophilic proteins. Phylogenetic analysis showed that CmCA3, CmCA4, and CmCA5 clustered into one group, while CmCA6, CmCA7, CmCA8, and CmCA9 formed another group. Meanwhile, CmCA1, CmCA2, and CmCA10 each formed independent group. Transcriptome analysis revealed that CmCA7, CmCA8, CmCA2, CmCA6, and CmCA10 were expressed at relatively low levels during the nauplius stage, while CmCA5 and CmCA3 showed high expression expressed during the metamorphosis mid-stage and juvenile stage, CmCA4 and CmCA1 exhibited high expression during the nauplius stage, while CmCA9 showed increased expression at the cyprid stage, followed by a significant decrease. In summary, the results of this study provide a theoretical basis for further understanding the regulatory mechanism of CA genes in the calcification process of C.mitella.