Abstract: In order to explore the mechanism of sexual development of freshwater shellfish, we established a gonadal transcriptome of Hyriopsis schlegelii. Based on the transcriptome library, this study investigated the β-catenin. The full-length cDNA was cloned by RACE PCR, which named Hsβ-catenin. The full length of Hsβ-catenin cDNA was 4386 bp that contained an open reading frame (ORF) of 2466 bp coding a protein of 821 amino acids. The protein was mainly composed of 12 ARM repeat sequences. In the secondary structure, the α-helix accounted for 47.75% and the β-folding accounted for 1.22% were predicted. The tertiary structure had many α-helixs, namely ARM domain. Hsβ-catenin gene was clustered with homologous genes from soft animal in the phylogenetic tree. Hsβ-catenin expressed highly in intes- tine and modestlyin foot and testis. The expression level of Hsβ-catenin was high at the age of 12-month-old (gender differentiation) and 36-month-old (gonad mature), indicated that it might be involved in sexual development.