Cr-doped hexagonal ferrites, with chemical composion Sr_0.35Ca_0.30La_0.35Fe_12.00−xCr_xO₁₉ (where 0.00 ≤ x ≤ 1.05), were synthesized using the traditional ceramic route. An X-ray diffractometer (XRD) and a vibrating sample magnetometer were used to characterize the phase composition and magnetic properties of the magnetic powders, respectively. The XRD data show that when the Cr content (x) ≤ 0.60, non-magnetic phase, α-Fe₂O₃, is obviously observed. When the Cr content (x) ≥ 0.60, the diffraction patterns demonstate that the magnetic powders show the magnetoplumite structure, and only a small trace of α-Fe₂O₃ is observed. The saturation magnetization linearly decreases with the increase of Cr content (x) from 0.00 to 1.05, while the remanent magnetization first increases with Cr content (x) from 0.00 to 0.45, and then keeps constant with Cr content (x) form 0.45 to 0.75, and decreases when Cr content (x) ≥ 0.75. The coercivity initially enhances significantly with the increasing of Cr content (x) until it reaches to the maximum value of 3925 Oe at Cr content (x) = 0.60, and then decreases slowly when Cr content (x) ≥ 0.60.