Abstract:ABSTRACT: Ribbons of the Fe53Nd37Al10 alloy with different cooling rates, 40 m/s and 20 m/s, were prepared by melt spinning method. The magnetic behavior, magnetic viscosity behavior and microstructure of the ribbons were investigated. The remanent magnetization Mr of the ribbons with the cooling rate of 40 m/s and 20 m/s is 33.50 Am2/kg and 36.05 Am2/kg, and the coercivity Hci is 62.00 kA/m and 121.50 kA/m, respectively. The fluctuation field Hf, activation volume Va and activation diameter Da of the ribbons with the cooling rate of 40 m/s are 2.47 mT, 3.90?0-18cm3 and 19.53 nm, respectively. The Hf, Va, and Da of the ribbons with the cooling rate of 20 m/s are 2.73 mT, 3.53?0-18cm3 and 18.89 nm, respectively. The size of nanoclusters in the ribbons with the cooling rate of 40 m/s is less than 5 nm. However, the size of nanoclusters in the ribbons with the cooling rate of 20 m/s is 5-10 nm and there are more nanoclusters in the ribbons. The hard magnetic property of the ribbons melt-spun at 40 m/s and 20 m/s would be due to the exchange coupling interactions and pinning effect. the size and amount of nanoclusters and the interactive units composed by many nanoclusters mostly affect the coercivity of the ribbons of Fe-Nd-Al amorphous alloy.