Centrifuging method was used to determine soil water characteristic curves of four undisturbed soils different in bulk density,and through the experiment,surfaces depicting quantitative relationship between mass water content,pressure head and bulk density in the four soil samples were obtained.Based on the measured data,effects of soil disturbance on the three-variable surfaces were analyzed,a fitting model proposed by the authors was verified,and fitting results of the packed and undisturbed soils were compared.Results show that soil disturbance obviously changed the soil three-variable surfaces.The bigger the difference in initial bulk density between packed and undisturbed soils,the greater the effect of soil disturbance on the surface. The differences in model parameters between the two treatments demonstrate the effects of soil disturbance on the three-variable surfaces.The study of soil three-variable surface for undisturbed soils is sure of some practical significance in extrapolating the study of soil hydrodynamics in soils different in bulk density to field soils.