Aiming at the problem of soil salinization existed inside oasis , grain-size of 84 typical samples in Ili Valley , Xinjiang Uighur Auto nomous Region was tested .Spatial variability of soil salinity in topsoil and its relationship with landscapest ructure were studied in combination of geo-stati stics methods .Results showed that mechanical composition of topsoil was mainly composed of silt and clay .Variation degree of silt and clay contents changed from the weak to the medium .Averaged diameter was gradually decreased and frequency curveex hibited a pattern with positive excursion , nearly symmetric excursion , and negative excursion from east to west .Structural factors like parent material and landform were the main factors which control the spatial dist ribution of surface soil particles .Random factors like irrigation and tillage intensified the spatial distribution of surface soil particles .It is the most important agro-ecolo gical problem that percentage content of silt was increased in mechanical composition of sag area .Soil hardening and secondary salinization were intensified in the sustainable utilization process of newly cultivated oasis resource .