Abstract: This paper reviews the development of high power neodymium laser glasses and their main properties. The emphasis is on the research progress of pot melting, continuous melting and cladding techniques for large aperture N31 neodymium phosphate laser glass developed by Shanghai Institute of Optics and Fine Mechanics. The main properties of N31 glasses, prepared by pot melting and continuous melting, are compared. The attenuation at laser wavelength, fluorescent lifetime and small signal gain coefficient of N31 glasses at different Nd2O3 doping level are also reported. One thousand times testing on the cladding of 400 mm aperture N31 glass had been finished, in which the pumping density of Xenon lamps was almost the same as that in Shenguang Ⅲ facility.