The techniques of Rapid Amplification of cDNA Ends were used to clone the Penaeus monodon calreticulin gene (PmCRT). The full length cDNA of PmCRT contained a 5′untranslated region (UTR) of 37 bp, an ORF of 1 221 bp encoding a polypeptide of 406 amino acids with an estimated molecular mass of 46.8 ku and a 3′UTR of 414 bp. Sequence alignment analysis showed that the PmCRT and Fenneropenaeus chinensis shared a similarity of 100%, and a homology of 98.8%. The quantification result of PmCRT mRNA in 8 tissues of Penaeus monodon showed that，in ovary the highest levels，followed by muscle, intestines, stomach, eyestalk, hepatopancreas, heart and brain. Furthermore, the PmCRT expression was found to be at high level in the six ovarian stages of development and the expression of ovarian growth levels in the third growth phase was significantly higher than that of others, while the lowest in the first growth phase. The study provided essential materials and laid a firm foundation for the further research of the function of PmCRT in ovary development.