Abstract: The production of drought tolerant transgenic poplars is one of the effective ways to improve the ecological environment of arid regions.In this study,the expression of SacB gene in transgenic lines of Populus alba×P.glandulosa was analyzed by RT-PCR and the drought tolerance of those transgenic lines was evaluated by water stress trial in greenhouse.The results showed that the transcription of SacB was detected in all transgenic lines and the fructan accumulated in the leaves of those plants.The growth,biomass and leaf water content of some transgenic lines were significant higher than those of the control under water stress.The correlation analysis indicates that the concentration of fructan in leaves of transgenic lines is most significant positively related to growth,biomass and leaf water content.The results also show that the expression of SacB gene in transgenic poplar enhances its resistance to water stress.