In situ measurements with a Guelph Permeator were performed to investigate the saturated hydraulic conductivity of soils (Kfs) at various desertified sand lands, such as grassland, fixed sand dune and mobile sand dune of Horqin Sand Land. Based on analyzing the relationships of Kfs with the sand land types, soil depths, slope position of sand dunes and soil physical and chemical properties, the results indicated that: (1) The average Kfs increased in the order: grassland (potential desertification), fixed sand dune (light desertification) and mobile sand dune (serve desertification), and the value was 2.15, 4.79 and 5.89 mm min^-1, respectively. That was, the more serious desertified, the higher infiltration capacity. A statistically significant differences (p<0.05) in Kfs were found among the three sites and between the slope positions of the two dunes. So, the Kfs at Horqin Sand Land has showed a higher heterogeneity; (2) The changes of Kfs was considerably with the increase of soil profile depths. The changes of Kfs with soil depths at grassland could be fitted with parabola models, and for fixed sand dune by exponential models; (3) The stepwise regression revealed that the soil organic matter content, the fine sand fraction (0.1~0.05 mm) and the clay and silt content (<0.05 mm) were some key factors affecting Kfs with a significantly negative relationship, but there was a significantly positive correlation with the coarse sand fraction (2~0.1 mm).