Abstract: The secondary electron emission characteristic of pyrolytic graphite,high-purity isotropic graphite and copper are introduced,and the effect of ion beam surface modification on secondary electron emission characteristic is also descriped.The results indicate that the secondary electron emission yield of pyrolytic graphite and high-purity isotropic graphite are apparently lower than the secondary electron emission yield of copper,and their secondary electron emission yield can be further reduced by ion beam surface modification.Similarly,the secondary electron emission yield of ion-textured copper has certain degree of reduction,and there is still large space for developmemt.