To elaborate soil moisture and grain size characteristics of 3 typical micro-areas in Minqin oasis-desert ecotone, samples were collected in runoff generation area and accumulated area using soil profile and multi-point sampling method, for soil moisture and physicochemical property analysis. Research results that (i) water accumulation trace of accumulated area is significant and the vegetation coverage is larger than the runoff generation area. The crust development in clay sand barrier + Haloxylon ammodendron forest accumulated is better than runoff generation area, while the situation is contrary in Nitraria tangutorum sand dune lowland and clay flat land. (ii) Moisture of accumulated area in fixed Nitraria tangutorum sand inter-dune lowland is better than the runoff generation area; the moisture of accumulated area in clay flat land topsoil is significantly better than the runoff generation area, while the topsoil moisture of clay sand barrier + Haloxylon ammodendron forest is better in the runoff generation area than in the accumulated area. (iii) Soil moisture of accumulated area in 3 types of micro-areas is in the range of 20-40 cm; the fixed Nitraria tangutorum sand inter-dune lowland is better than clay flat land and clay sand barrier + Haloxylon ammodendron forest, while the lowest moisture of corresponding runoff generation area is basically consistent with the depth. (iv) The topsoil clay and powder content in accumulated area of fixed Nitraria tangutorum sand inter-dune lowland is lower than the runoff generation area, while the fine sand content in deep layer of runoff generation area is greater than the accumulated area; soil in two areas of clay flat land mainly consists of coarse and fine sand, and clay particles are better in runoff generation area than in accumulated area. Soil in the clay sand barrier + Haloxylon ammodendron forest is mainly coarse sand and the structure is single. In sum, through adjusting allocation of rainfall, micro-areas influence soil moisture and grain size distribution, and further influence spatial - temporal distribution of vegetation in sand micro-areas.