New anionic polyelectrolyte gels were prepared by the chemical crosslinking reaction of highly phosphorylated poly(vinyl alcohol) (P-PVA) with glutaraldehyde. The structures of the gels were determined by both i.r. and solid-state C-13 n.m.r. spectroscopy. The various types of polyanionic gels having high- or low-swelling characteristics and different degrees of hardness could be prepared by using the crosslinking reaction under different reaction conditions. The gels with low crosslinking densities showed in the order of 500 gg(-1) of the maximum absorbency value. The thermal properties of the chemically crosslinked P-PVA were also investigated.