Abstract: Transcription factors are a kind of proteins that play an important role in the regulation of plant growth and development, as well as in plant response to environmental variation. They usually contain a DNA-binding domain, a transcription regulation domain, an oligomerization site and a nuclear localization signal inside their DNA sequence. WRKY proteins had been identified as one of the important transcription factors in plants. There have been 103 WRKY genes which were predicted in rice genome by data mining and the annotation of the biological function of these genes had the important value for the functional genomics of rice. SUSIRI gene was one of the WRKY transcription factor genes cloned from the Oryza sativa sub. Japonica var. Nipponbare and its ORF was 1755 bp long, encoding a polypeptide of 584 amino acids with two typical WRKY domains. In this study, based on nucleotide sequence of the SUSIRI gene, its biological function in gene regulation in rice had been further elucidated. Firstly, the structure and functions of the predicted protein were analyzed by bioinformatics tools while the Motif sequence of SUSIRI gene was analyzed by using EBI interpro database, the conserved domains of the protein was analyzed by NCBI CDD database; the hydrophilicity (hydrophobicity) of amino acid residues and the transmembrane domains of SUSIRI protein were analyzed by DNAMAN and CBS TMHMM. By using CBS Protcomp version 9.0 and Protfun software, the subcellular localization and function of protein were predicted. Secondly, the fluorescence expression vector of pNSUGFP driven by actin promoter was constructed by fusing the SUSIRI gene and GFP gene and was used to transform into epidermis cell of onion by Gene gun for detecting gene subcellular location. The prediction from bioinformatics showed that the SUSIRI gene had the greatest probability in function of transcription, transcription regulation or signal transduction in the rice cell with the value in prediction of 0.973, 1.598 and 0.602. Similarly, it had the greatest probability in participation of translation, central intermediary metabolism, fatty acid metabolism with the predicted value of 4.800, 1.490 and 1.265. Because of high content of hydrophilic amino acid residues among peptide sequences, the SUSIRI protein had hardly inserted into the membrane in the cell when it was likely to be localized within the cell nucleus since the strong nucleus location signal was detected from the sequence of amino acids. By using the fluorescence microscopy to observe the onion epidermic cells, the GFP protein was shown to express along the cell wall in the control, but the fused protein of SUSIRI-GFP expressed strongly in the cell nucleus. The result indicated that the SUSIRI gene was likely to be the transcription factor regulating the intermediary metabolism in rice and playing the role during the gene transcription. SUSIRI protein could be localized in nucleolus which is an obvious feature of transcription factor of SUSIRI gene determined by the experiment.