Abstract: The amorphous structural paramete rs of the amorphous Sm₅Fe_74.3Nb_1.5Si_11.7B_4.5C_2.3Cu_0.5 alloy,short-range order and nearest neighbour distance,were investigated by using XRS method under the condition of preannealing at dif ferent temperature and for different time.The influence of preannealing on amorphous structure was discussed.Experimental results show that the short-range order increases obviously with the increa sing temperature lower than 400 ℃,beyond which short-range order decreases and nearest neighbour distance increases.The values of short-range order and nearest neighbour distance reach the limit at 400 ℃.Preannealing at 500 ℃ for different time,short-range order increases with time,while nearest neighbour distance decreases.