We evaluated the effect of ferritin on the ability of the swimming crab to adapt to salinity stress. We amplified the gene from the sixth gill of the swimming crab and cloned it into the pET 28 a (+) expression vector. The vector was DE3 (BL21) and induced by IPTG. The erritin protein was successfully induced by IPTG, yielding a band that was consistent with the theoretical value (19.448 kD). was higher than that of empty vector transferred cells. Furthermore, the recombinant plasmid significantly improved the tolerance of Our results suggest that P. trituberculatus.