Drought is one of the most critical factor limiting the potato yield and quality. Abscisic acid (ABA) is the essential part of drought responsing regulatory networks and 9-cis-epoxycarotenoiddioxygenase (NCED) is the keyrate-limiting enzyme ofABA biosynthesis in higher plants.It directly influences the expression pattern of ABA metabolism. However, there are few reports on relationship among NCED expression pattern, ABA content and phenotypic changes on potato. In this research, A NCED gene (StNCED1)has been cloned from potato and NCED expression levels, ABA content and root length changes was evaluated in 4 varieties under simulated drought stress by different concentration of PEG‐6000. The results showed that the full length of StNCED1 was 2181 bp, which contains a 1803 bpopen reading frame (ORF) encoding a protein of 600 amino acid residues.Analysis showed that all the 4 varieties seedling growth was significantly inhibited, and especially the root length decreased sharply with the stress concentration increased from 5% upto 15%. Drought sensitive material“zaodabai” showed the most obvious changes in root length among the 4 tested materials and the ABA content is significantly higher than the other three materials. The expression level of StNCED1 in drought stressed plant was significantly higher than the control group of CIP478.9, star and mila, respectively. The expression levels of were increased with increasing concentration of PEG‐6000 in these three materials. On the opposite, StNCED1 expression and ABA content showed a decrease at first and then an increase trend in “zaodabai”. A positive correlation (R>0.7) was proved between ABA concentration change and StNCED1 expression level in all the 4 tested materials under drought stress. Our results will provide fundermental data for further revealing the regulation mechanism ofStNCED1 responsing to drought stress and will be helpful in screening drought resistance germplasm resources.