Abstract: At present, engineering disasters caused by expansive soil have attracted worldwide attention. At home and abroad, studies on the improvement of expansive soil have been conducted by many engineers, while literatures on the application of wasted tire rubber powders to improve the strength of the expensive soil are few. In order to increase the use of the recycled resources and reduce the harmful impact of the expensive soil on the engineering, the author conducted a series of explorations to study whether and how the wasted tire rubber powder can improve the expensive soil. In the course of the study, wasted tire rubber powder in different proportion with different water content is mixed with expansive soil to make different ESR( expansive soil-rubber). The result of the test shows that the internal friction angle and the shear strength of the expansive soil increase as the amount of the wasted tire rubber powder increases. And the test also shows that the internal friction dose not have a remarkable change, while the cohesion changes much. This result confirms the assumption that wasted tire rubber powder can improve the expansive soil greatly. This finding opens up a new improving method to reduce the engineering disaster caused by the expensive soil.