We developed a web server GSDS (Gene Structure Display Server) for drawing gene structure schematic diagrams. Users can submit three types of data：CDS and genomic sequences, NCBI GenBank accession numbers or GIs, exon positions on a gene. GSDS uses this information to obtain the gene structure and draw diagram for it. Users can also designate some special regions to mark on the gene structure diagram. The output result will be PNG or SVG format picture. The corresponding sequence will be shown in a new window by clicking the picture in PNG format. A Chinese version for the main page is also built. The GSDS is available on http://gsds.cbi.pku.edu.cn/.