Plant can suffer seriously in the process of growth and development, thus limits crop productivity under cold stress conditions. We identify 32 C. maxima glutathione- transferases (CmaGST) genes, and characterized them by expression profiling. We found tau is the major classes of GST in pumpkin. Large numbers of GST genes in pumpkin were expanded through gene duplication, 11 and 5 pairs of CmaGST genes were segmental and tandem duplicated, respectively.Under cold condition, six genes (CmaGSTU7, CmaGSTU8, CmaGSTU9, CmaGSTU11, CmaGSTU12, and CmaGSTU14) showed higher expression in cold tolerance cultivar in response to cold stress.