Glass is a kind of difficult-to-machine material due to its hard and brittle properties. Although many special hole machining methods for brittle and hard materials have been developed, the traditional drilling is still widely applied because it is simple and reliable. However, the drilling tool for hard and brittle material is an obstacle, especially for small hole drilling. In this paper, two types of diamond abrasive core-tools which are made by electroplating and sintering process are used to machine small holes in glass plates, their structures are introduced and their machining performances are compared. The experimental result indicates that these diamond abrasive tools are satisfied for small hole machining in glass, and the performance of electroplating tool is better than that of sintering one.