Plants SWEET gene family is a kind of sugar transporter, which plays an important role in plant physiological activities and growth and development.In order to understand the information related to potato SWEET gene and explore its expression characteristics in different potato tissues and under biological and abiotic stress, we cloned the StSWEET5 gene from potato ‘Qingshu 9’ using homologous cloning technology(GenBank accession number is MN295671), whose CDS sequence length was 717 bp and encoded 238 amino acids.Phylogenetic tree analysis showed that the amino acid sequence similarity between the protein and that of tomato was the highest, reaching 97.06%. The results of qRTPCR showed that StSWEET5 gene was expressed in all tissues of potato (root, stem, leaf, flower, tuber and stolon), with the highest expression in flowers. StSWEET5 can be expressed in rhizomes and leaves under sugar stress, especially in roots (P<0.05). After 36 h induction of Phytophthora, the expression of Phytophthora in leaves was significantly uprated. It is speculated that StSWEET5 gene is involved in potato sugar stress and responds to late blight induction.