In this study, we generated and characterized the transgenic rice plant expressing a spider silk protein. A cDNA coding for the C-terminus of spider dragline silk protein (AvDrag) was cloned from the spider Araneus ventricosus. Analysis of the cDNA sequence shows that the C-terminus of AvDrag consists of 165 amino acids of are petitive region and 99 amino acids of a C-terminalnon-repetitive region. The peptide motifs found in spider drag line silk proteins, GGX and An, were conserved in the repetitive region of AvDrag. The AvDrag cDNA was expressed as a 28kDa polypeptide in baculovirus-infected insect cells. To produce transgenic rice plant with high contents of glycine and alanine, the prolamin promoter-driven AvDrag was introduced into rice plant via Agrobacteriumtumefaciens-mediated gene transformation. Because of seeds pecific prolamin promoter, expression of AvDrag protein has been achieved inriceseed. The introduction and copy number of the AvDrag gene in transgenic rice plants were determined by PCR and Southern blot analysis. AvDrag expression in transgenic rice seeds was examined by Northern blot and Western blot analysis. Immuno fluorescence staining with the AvDrag antiserum revealed that the recombinant AvDrag proteins were localized in transgenic rice seeds. Furthermore, the amino acid content analysis showed that transgenic rice seeds were greatly increased in glycine and alanine as compared to controls. The present study is the first to show the expression of spider silk protein in rice seed.