To slow down the accumulation of reducing sugar in potato tubers exposed to low-temperature storage, an expression vector, pBICNI, including Nt-VIF (Nicotiana tabacum vacuolar inhibitor of beta fructosidase, a vacuolar invertase inhibitor from Nicotiana tabacum) gene regulated by potato tuber specific promoter class I patatin promoter (CIPP) was constructed and transformed into potato (Solanum tuberosum L.) cultivar E-potato 3 (E3). Detection by polymerase chain reaction (PCR), Northern and Southern hybridizations indicated that the full-length Nt-VIF cDNA was transformed successfully into cv. E3. After storing potato tubers of 14 transgenic lines at 4 or 20°C for 30 days, their activities of vacuolar invertase (VI) and reducing sugar (RS) content were analysed. The results showed that there were no significant differences in RS content between transgenic and untransformed (control) tubers stored at 20°C. However, RS content of transgenic lines was obviously reduced at 4°C compared to the control, from 34.0% (line B-13) to 76.8% reduction (line B-1), implying that VI activity was inhibited by Nt-VIF cDNA expression and RS content was reduced. Further analysis revealed a positive linear relationship between VI activity and RS content (VI=0.308RS+0.067), and lines B-1, B-2, B-6, B-9 and B-14 could meet the requirements of potato chips in terms of their low RS content after cold storage.