The formation and directional arrangement of silver halide nanorods in glass and their influences on the polarization properties were investigated. The results show that silver halide particles are easier to precipitate in a sodium boron rich phase. The optimum heat treatment condition for the crystallization is at 615 ℃ for holding time of 12 h. The formation and orientation of silver halide nanorods in glass is a winning combination of glass stretching temperature, stress and speed. The average diameter of AgCl nanorods in glass is 98 nm, the average length is 558 nm, the average aspect ratio of the nanorods is 1:5.6, and the nanorods are oriented along the stretching direction of glass when the stretching temperature is 570 ℃, the stress is 735 N, and the speed is 120 mm/min. According to the polarizing property of glass after high-pressure reduction, the more AgCl nanorods in the unit area of the stretched glass surface is, the higher the extinction ratio of the reduced glass will be.