Tropomyosin is a main allergen in Decapod; however, studies on its other aspects are very limited. In this study, tropomyosin mRNA sequence in P. clarkii was cloned and the homologous sequence alignments were conducted. The transcriptional levels of the gene during the ovarian development of P. clarkii were quantified. The results showed that the tropomyosin amino acid sequence was highly conserved in decapod crustaceans and eight antigen decision cluster sequences were almost exactly the same. There were three nucleotide positions changes (c61—t, g118—a, c359—t) in the new cloned sequence, but the immunogenicity was not affected because they were not within in the antigenic determinant (AD). Although the Tropomyosin mRNA level in P.clarkii ovarian tissue was very low, its differences in different developmental stages were still detected. In brief, the expression of the tropomyosin gene showed a peak type pattern (first increased, and then decreased). This study suggested tropomyosin, a allergen, is partially regulated by the gonadal development.