Abstract: To clarify the Minqin desert area three kinds of micro-area soil moisture and grain size characteristics change，In its water runoff area and accumulated area using mixed soil profile and multi-point sampling method for the analysis of soil moisture and grain size characteristic properties ,The results showed that:(1)Water content and Condition of vegetation of water accumulated area are significantly larger than the runoff area in three types of micro-area. Growth of Crust of water accumulated area are better than water runoff area in Clay sand barrier Haloxylon forest, on the contrary, Crust of water runoff area growed better than water accumulated area in the lowland of Nitraria schobei sandbags and clay plains. (2)The water content of water accumulated area are better than the runoff area in lowland of fixed Nitraria schobei sandbags. And water content of surface layer of water accumulated area are better than the runoff area in clay plains, but the runoff area is better than water accumulated area in Clay sand barrier Haloxylon forest. (3)The Low water content of water accumulated area are between 20 and 40 cm. And lowland of Nitraria schobei sandbags are significantly larger than clay plains and Clay sand barrier Haloxylon forest. the corresponding of the runoff area, its water content and soil depth are basical Consistency. (4)The content of clay, silt are large in surface layer of water accumulated area of lowland of Nitraria schobei sandbags, on the contrary, fine sand are more in the runoff area ; The mainly parts of clay plains are fine sand and coarse sand. Besides, Clay content in the corresponding of layers, the runoff area are better than water accumulated area. Clay sand barrier Haloxylon forest are mainly composed of the coarse sand, But its structure is very simple. In short, the micro-area by adjusting the distribution of precipitation to influence the effect of the soil moisture and grain size distribution and the sand area vegetation space-time distribution.