Drought is a major environmental stress that limits potato (Solanum tuberosum L.) production worldwide. The transcription factor DREB1A/CBF3 specifically interacts with the dehydration responsive element (DRE/CRT) and induces expression of genes involved in environmental stress tolerance in Arabidopsis thaliana. In this study, DREB1A of A. thaliana was overexpressed in a potato cultivar Longshu 3 (L3) through Agrobacterium tumefaciens-mediated transformation. The transformation and overexpression of DREB1A were assessed using PCR, Southern blotting and semi-quantitative RT-PCR analysis. The results clearly confirmed that the DREB1A gene was successfully integrated into the genome and expressed. When pot-grown plants with 15-16 leaves were subjected to drought stress treatments by withholding water for 8 days, the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), the MDA content and electrolyte leakage in leaves from both non-transgenic and transgenic L3 plants leaves increased. The average activities of SOD, CAT, and POD in transgenic plant leaves, respectively showed 69.77, 60.78, and 24.60% increase than those of non-transgenic L3. The MDA content and electrolyte leakage in non-transgenic L3 plant leaves, respectively increased 59.09 and 37.63% relative to those of transgenic plant leaves. When water was withheld for 14 days control plants exhibited severe wilting and transgenic plants only partially wilting. These results demonstrated that overexpression of DREB1A resulted in improved drought stress tolerance in S. tuberosum plants.