Hydraulic properties are strongly correlated to soil pore size distribution resulting from the arrangement of soil particles (textural effect) and from soil structure. The structural effect is especially strong at high pressure potentials (-0.1kPa to -10 kPa). Water retention properties are used to characterize pore size distribution, but there are few studies discriminating textural from structural effects on water retention. Our objective was to characterize soil structure by separating textural effects on water retention curves.  Undisturbed clod samples were taken from each of 3 horizons from soil profiles subjected to agriculture and forest land use. Clod bulk density was measured with the saran resin method and water retention curves with a hanging column (7 pressure potentials in the range from -0.1kPa to -10 kPa). Disturbed soil from measured clods was repacked to measure water retention (13 pressure potentials in the range from -0.1 kPa to -1500 kPa). Particle size distribution for each clod was measured with a laser diffraction technique. Structural effects were quantified as the difference in water content retained by the disturbed and undisturbed material over the -0.1 kPa to -10 kPa range of pressure potentials. The resulting function was assumed to represent the effect of soil structure and different strategies were used to characterize it. Correlation among parameter values from common water retention models, particle size distribution and bulk density will be discussed.