[Objective] Discussing the influence and the mechanism of a self-developed soil anti-erosion material on the water-stability property of soil aggregates to provide a better theoretical insight for the treatment of sloping farmland.[Methods] Investigating the changes of red soil aggregates water-stability used a self-developed polysaccharide polymer soil anti-erosion material named SA-01.[Results] The soil aggregates water-stability became 2.6 times of the original ones after 0.25% SA-01 treated and became 100% after 1% SA-01 treated.[Conclusion] The SA-01 could greatly enhance the water-stability property of red soil aggregates and the thin permeable film which was formed on the surface of soil was the key factor to the enhancement.