Abstract: In order to study the soil-water characteristics of fiber modified expansive soil，soil water characteristic curve( SWCC) was tested． An expansive soil sampling from an engineering site in Hefei was taken as a research object，and three dry densities and four fiber contents were considered in the experiment． Then，the experimental results were fitted by using the van Genutchen model． The result showed that the effect of dry density on the SWCC of fiber modified expansive soil were obvious． With the increase of dry density，the degree of saturation increase for the same matrix suction． However，the effect of fiber’s content on the SWCC for fiber modified expansive soil was irregular． The curve fitting parameters and their statistics of SWCC for fiber modified expansive soil were obtained by curve fitting． And it was pointed out that the variability of parameter n and ws were smaller． The variability of parameter m was moderate，while the variability of parameter a and wr was more larger．