Abstract: Calcium-activated chloride channel regulator（CLCA） is a metalloproteinase-dependent family protein and plays an essential role in goblet cell mucus production and balance from the epithelium in mammals. In order to figure out the osmotic pressure regulation of CLCA1 in Litopenaeus vannamei, we cloned full-length of CLCA1 cDNA by RACE technology. The total length of the gene was 3 129 bp, with the length of the 5’-terminal non-coding region of 175 bp, the length of the 3’-terminal non-coding region of 107 bp, and the ORF length of the open reading frame of 2 847 bp. It encoded 984 amino acids in total, with one transmembrane region, and a VMA structure domain outside the membrane. The results of amino acid sequence comparison with other species showed that the CLCA1 amino acid of Litopenaeus vannamei was not similar to the other species, the highest similarity was the CLCA2 amino acid sequence of Procambarus clarkii, which was 47.83%. RT-qPCR results showed that CLCA1 gene was expressed in all tissues of Litopenaeus vannamei, the expressions were higher in intestine, gill and hepatopancreas. Results showed the expression of CLCA1 gene was down-regulated in four tissues as salinity decreased which meant that CLCA1 was involved in osmotic pressure regulation of Litopenaeus vannamei. The experiment initially clarified the physical and chemical properties of CLCA1 gene and quantified CLCA1 gene expression in different tissues of litopenaeus vannamei under different salinity. These results provided basic support for future studies on the role of CLCA1 gene in osmotic pressure regulation in crustaceans.