Abstract: The erosion-abrasion wear properties of eutectic Al-Mn alloy and its Al2O3 particle reinforced composites were studied at erosion-abrasion rate of 7 m·s-1 and 15 m·s-1 in rotating erosion-abrasion wear test, and the microstructure characteristics and the worn surface of the materials after erosion-abrasion wear test were analyzed. The results show that, the cast Al-Mn alloy was composed of Al-Mn solid solution, MnAl6 and Al11Mn4 phase, while Al2O3 particles appeared in the composite besides the aforementioned microstructure. The wear rate at the erosion-abrasion rate of 15 m·s-1 was 20 to 30 times as large as the wear rate at the erosion-abrasion rate of 7 m·s-1 for two materials. And the major factor of wear rate was erosion-abrasion rate. The wear rates of both materials were higher with 3% abrasive addition than with 1% abrasive addition, and exhibited increase first then decline with increase of abrasive diameter. The maximum wear rate moved toward the abrasive in larger diameter with increase of erosion-abrasion rate when abrasive addition was 1%. The Al2O3 particle reinforced composite exhibited a good erosion-abrasion wear resistance because of dispersion strengthening of Al2O3 particles distributed uniformly in matrix at same erosion-abrasion conditions.