A Y 3 (Fe, Cr) 2 9 single crystal which has a Nd 3 (Fe, Ti) 2 9 -type monoclinic structure has been prepared using the Czochralski method followed by heat treatment of an initial Y 2 (Fe, Cr) 1 7 crystal. The magnetization curves were measured along the easy and hard magnetization directions in the range from 1.5 to 293 K for crystals of Y 3 (Fe, Cr) 2 9 and Y 2 (Fe, Cr) 1 7 . The saturation magnetization of Y 3 (Fe, Cr) 2 9 decreases with increasing temperature and is in good agreement with a T 3 / 2 spin-wave relation law. The magnetic properties of the two crystals are compared.