SmFe₃ single crystal was grown by a self-flux method using Sm as a flux, and its crystallographic and magnetic properties have been studied. SmFe₃ crystalizes in the rhombohedral PuNi₃-type structure and has lattice constants of a=0.5179 and c=2.4795 nm. The saturation magnetizations M _S at 5 K and 300 K are respectively 89.9 emu/g and 80.7 emu/g, and the Curie temperature is 644 K. The anisotropy constants K ₁ and K ₂ at 5 K are -2.69×10⁷ and 11.9×10⁷ erg/cm³ and at 300 K are 2.36×10⁷ and 2.21×10⁷ erg/cm³. While the easy direction of magnetization is parallel to the c-axis at 300 K, it lies on the surface of a cone below 160 K. The angle θ between the c-axis and the generatrix of the cone is about 31° at 5 K.