At5NC056820 of Arabidopsis thaliana overexpressing vector was constructed by dipping method and 12 strains of overexpression lines were obtained by semiquantitative PCR. The physiological indexes of transgenic plants under drought stress were analyzed to research the relationship between At5NC056820 and drought stress, which provided the basis for revealing the molecular mechanism of lncRNA affecting plant drought resistance. The results showed that: (1) the vector containing At5NC056820 was sucessfully constructed and 12 positive plants were obtained. (2) At5NC056820 was overexpressed in Arabidopsis thaliana which were confirmed by RCR; the transgenic plants A3, A7 and A8 grow better than wild plants under drought treatment. (3) After 10 days of drought treatment, the free proline content of transgenic Arabidopsis was 2 429.58 μg·g^-1, which was 2.2-2.5 times higher than that of wild type. The chlorophyll content of transgenic Arabidopsis was 0.82 mg·g^-1, which decreased by 48.9% on average, while that of wild type Arabidopsis decreased by 63.0%. The content of malondialdehyde (MDA) was 2.15 mmol·L^-1·g^-1, which was 1.19 mmol·L^-1·g^-1 ouer than that of wild type, and the relative water content of transgenic Arabidopsis was 53.73% and 19.0% lower than that of wild type. The result shows that lncRNAAt5NC056820 could increase the drought resistance of A. thaliana.