The fabrication of borate glasses containing BaFe12O19 crystal by incorporation method was studied. From transmission electron microscopy observation, there is only one hexagonal crystalline phase identified as BaFe12O19 existing in glass matrix. The average transmittance of the incorporated samples decreased from 39% to 2.4% when the BaFe12O19 content increased from 5 to 12.5 wt%. When the content of BaFe12O19 is 10 wt%, the as-cast sample shows a Faraday rotation of 30.05 degrees/cm and a magnetization of 0.58 emu/g in a field of 14 kOe. (c) 2005 Elsevier B.V. All rights reserved.