The main properties of high-power Nd∶laser glass in China and abroad and its development situations were compared. Then, the physical properties of large aperture N41 Nd∶glass developed by Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences(SIOM) were analyzed and its gain characteristics in a segment amplification system with an aperture of 400 nm was investigated. An optimized technological scheme was used to measure the small-signal net-gain parameters of N41 glass and N31-42 glass and the gain homogeneity of large aperture glass under the same condition. The results indicate that the several key parameters of N41 glass are better than that of the N31 glass. Under the same pumping condition, the average small-signal net-gain parameters for N41 glass and N31 glass are 5.3% and 5.16%, respectively, much better than the online experimental result of N31-35 glass used in Shenguang-Ⅲ. Moreover, the gain homogeneity of N41 glass with an aperture of 385 mm is 1.085∶1, and its cladding glass meets the requirement of Shenguang-Ⅲ. It concludes that the gain characteristics of the N41 glass have been improved greatly as compared with that of the N31 glass. When the amplifier structure is optimized, the N41 glass can be used in the Shenguang system in the future.