Abstract: We studied the amino sequenceof DlNAC1 gene(GenBank accession number EF602304) cloned from Dendranthema lavandulifolium by bioinformatics methods, and the DlNAC1 gene was transformed tobacco plants by Agrobacterium tumefaciens mediation method. Thepredicted DlNAC1 proteinhad hydrophilicity, and the second structure of this protein was mainly random coil. The NAC protein had six motif models and one NAC domain. The 36 of 55 transgenic tobacco plants were positive by PCR analysis. The heat stress tolerance of PCR positive tobacco plants was increased comparing with the wild plants. With 45℃ treatment for 6 h, the transgenic plants looked much stronger, whereas the wild type looked very weak with wilting leaves. The water content of transgenic plants was more than wild plants. However, the low temperature tolerance of the transgenic plants was not improvedafter 4℃ stress. All these results indicated that DlNAC1 gene improved the tolerance ability to the high temperature stress of transgenic tobacco plants.