We reviewed our structure studies on poly(vinyl alcohol) (PVA) gels formed in the mixtures of dimethyl sulfoxide (DMSO) and water using various scattering methods, including wide-, small-and ultra-small-angle neutron scattering and light scattering. These studies revealed the hierarchic structure of PVA gels formed in DMSO/water (60/40 v/v) in a very wide spatial scale from 1 A to several micrometers. The crosslinking points are crystallites with radii of similar to 70 angstrom, the distance between the neighboring crystallites is 180-200 angstrom, and the bicontinuous structure due to liquid-liquid phase separation is in mu m scale. We also review our dynamic studies on three kinds of PVA gels at the nanometer scale using neutron spin echo techniques to separate the concentration fluctuations observed by small-angle neutron scattering into the static and dynamics contributions. Polymer Journal (2012) 44, 83-94; doi:10.1038/pj.2011.88; published online 19 October 2011