β-1,3-glucan polysaccharides such as curdlan and schizophyllan adopt a triple helix structure in nature. The sense and the pitch of these β-1,3-glucans are comparable to those of polynucleotides. This structural similarity brought us the finding that β-1,3-glucans interact with particular polynucleotides to form helical, triple-stranded macromolecular complexes (two polysaccharide-strands and one polynucleotide-strand). The present article reviews the fundamental properties and structural studies of this novel complex. In the later part of the article, we describe possibility to use β-1,3-glucans polysaccharide as a gene carrier, due to its unique inherent ability to form a biological stable helix. In particular, the chemical attachments of cell-adhesion molecules into β-1,3-glucans remarkably enhanced the cell uptake efficiency of the resultant polysaccharide/polynucleotide complexes.