Brittle materials such as glasses, glass ceramics and ceramics are normally categorized as difficult to machine materials for its high hardness, brittleness, corrosion resistance and melting temperature. However, they have attracted much attentions and been playing critical roles in many applications in various areas for their advanced properties. Micro-patterns such as micro-hole (array) of various sizes and shapes are frequently required to be generated on brittle materials. In comparison to other non-traditional machining process, abrasive jet machining has the advantage of low cost and high efficiency and very limited heat affected zone. However, tapering angle and form error are normally the consequences of abrasive jet machining. Efforts have been made to minimize the down side of AJM and improve form accuracy by systematically study the influence of machining parameters such as abrasive grain size, stand-off distance and hybrid machining. Holes with form error less than 0.06 mm, tapering angle in the range of 48~50° are successfully produced on a glass plate of 0.4 mm in thickness..