Charonia sauliae, the largest sea snail is designated as the class I endangered species of red list data in Korea, because of habitat destruction and environmental pollution. For the conservation and restoration of this species, identification of genetic resources through transcriptomic and genomic studies, and investigation of ecological information are needed. In this study, we identified aquaporin (AQP) which plays an essential role in the water channel, by local-blast analysis with the nucleotide database of C. sauliae generated by Illumina Hi-Seq 2000 next-generation sequencing platform. AQP of C. sauliae contained 897 bp of nucleotides encoding 299 amino acid residues. The domain analysis of AQP showed one aquaporin-like domain including six transmembrane domains, eight amino acid residues which are related to the amphipathic channel, and two Asn-Pro-Ala signature motifs (NPA boxes). 3-Dimensional analysis indicated that it included six alpha-helix structures, which formed the transmembrane channel. To understand the evolutionary-relationship of AQP, conducted the multiple alignments and phylogenetic analysis, resulting in that AQP contained highly conserved NPA boxes and transmembrane domain. AQP of C. sauliae was localized in the same branch with Pomacea canaliculata (Ampullariidae). In the future, our results provide valuable information for the functional characterization of marine invertebrate aquaporin.