Abstract: A superoxide dismutase gene was cloned by the Cu /Zn-superoxide dismutase gene ( Cu /Zn-SOD) from cucumber and watermelon has cloned in NCBI, which was named HmCu /Zn-SOD.The length cDNA of HmCu /Zn-SOD was 403bp.The characteristics were analyzed and predicted by the tools of bioinformatics.The results showed that HmCu/Zn-SOD was a hydrophilic, non-transmembrane and non-secretory protein.The main motif of Cu/ZnSOD in secondary structure was random coils and extended strands.Despite sequence variations, the structure and the composition of amino acid sequences of HmCu/Zn-SOD were highly similar to that of other green plants.