The soil composition of aggregate and its stability, in Cransu Jingtai electricirrigating area, were studied in this paper. The results showed that the content of aggregate is low and its stability is poor. When moistened, much a large portion aggregate is detached. Clay has the greatest influence upon aggregate and its stability, this means that clay currently is the most important aggregating agent the role of CaCO₃, as aggregating agent, is the second and that of organic matter is the last because of its low content. However, the influence of organic matter upon aggregate's stability is greater than that of CaCO₃. Soluble salts make the content and stability of aggregate decreased. The study of microaggregate demonstrated that nearly all of particles <0.005mm are distributed in microaggregates >0.01mm, indicating that clay <0.005mm is aggregated perfectly, and structure coefficients of nearly all soils reach one handred percent. The effect of CaCO₃ on clay's aggregation is significant but organic matter plays minor role. Soluble salts has the trend detaching clay.In point of structure state and factors affecting its stability, soil wind erosion,low organic matter content and soluble salts accumulation were main reasons responsible for structure degeneration. The improvement and reconstruction of soil structure must go on with increase in organic matter, avoiding salinization and wind erosion and the improvement of ecological surroundings.