To elucidate the biosynthetic pathways of potato terpenoids, we identified a terpene synthase gene named as StHcS from potato genome data. StHcS was successfully cloned from potato variety ‘Feurita’ with infection of Phytophthora infestans by RTPCR. Bioinformatics analysis, biochemical characterization and gene expression pattern analysis were conducted for StHcS. The results are as follows: (1) the coding sequence length of StHcS is 1 497 bp and it eventually encodes 498 amino acids with a molecular mass of 74.78 kD; (2) the encoded StHcS contains the conserved DDXXD catalytic motif, and exhibits the highest similarity to the hedycaryol synthase in Camellia maliflora; (3) in vitro assay and E. coli metabolic engineering experiments reveal that StHcS can react with trans farnesene pyrophosphate (FPP) to produce the sesquiterpenehedycaryol; (4) RTPCR analysis indicates that StHcS can be induced by infection of P. infestans in potato tubers and the highest expression was observed at 72 h post inoculation. Hedycaryol was also successfully detected in the infected potato tubers by GCMS analysis. The identification of StHcS biochemical function provides diversity for the studies regarding sesquiterpene synthase, and it is also the first hedycaryol synthase found in potato, which provides a reference for the analysis of potato terpene biosynthesis.