Faraday rotatory glass has been used for modulating,deflecting of laser,optical switch and isolator.The main property of Faraday rotatory glass is the Verdet constant.Faraday rotatory glass containing high paramagnetic ion concentration is of the large Verdet constant,transparency in the visible region of light.Terbium ion with larger magnetic moment and lower f-d transition energy gap should possess the large Verdet constant.Based on the Tb2O3-B2O3-Al2O3-SiO2 system with high terbium oxide content,the glass formation region was determined and a linear relation between Tb3+ concentration and the Verdet constant was established.Faraday rotatory glass series of TG20,TG28 and TG32 with the Verdet constant of 75.1-116.4 rad/(T·m) was developed by modifying the glass composition to avoid devitrification.A melting furnace of 10 liters platinum crucible,forming apparatus and fine annealing skin were built up to produce 30 cm aperture Faraday rotatory glass.The glass is provided with an optical absorption coefficient of less than 0.008 cm-1 at 1054 nm,a laser damage threshold of larger than 8 J/cm2 at 1 ns pulse width,a transmitted wavefront distortion of less than λ/5 at 632 nm.The glass has been used for high power systems of LLNL in US,upgraded “Shenguang Ⅱ” in China,Vulcan laser system of Ruthorford Lab.In UK and Luli Laser System of CNRS,CEA in France.