Polycrystalline alloys Dy 1−x Pr x Fe 1.9 (0≤x≤1) were synthesized by arc-melting and subsequent high-pressure annealing. Their crystal structure, magnetic properties and magnetostriction have been investigated. X-ray diffraction results show that the system exhibits almost single cubic Laves phase with MgCu 2 -type structure over the whole range. The lattice parameter of the cubic Laves phase increases linearly with increasing Pr concentration, while the Curie temperature goes the opposite way. The saturation magnetization for Dy 1−x Pr x Fe 1.9 decreases with the increase of x and reaches a minimum at x=0.4, then it continues to increase with further increase of x, which reflects the antiparallel magnetic moment of Dy and Pr. The magnetostriction λ || −λ ⊥ first increases and then decreases within the range of 0.0≤x≤0.4, and increases monotonically with further increasing x.