The present invention relates to a transcription factor of a plant, AtSIZ, induced by osmotic stress; a gene encoding the transcription factor; and a method for enhancing resistance to stress of a plant by using the gene. The AtSIZ protein isolated from Arabidopsis thaliana is a polypeptide, which contains a C.sub.3H-type zinc finger motif and acts as a transcription regulation factor activating transcription of genes related to stress response of a plant. Therefore, a plant with the enhanced resistance to osmotic stress can be produced by over expressing the AtSIZ gene in the plant through transforming recombinant plasmid containing AtSIZ gene into a plant and consequently, the productivity of the plant can be increased.