An abrasive aided electrical discharge machining (AEDM) method is developed to improve the performance of conventional EDM process in machining particulate reinforced metal matrix composites (MMCs). This paper makes a contrastive research on material removal rate (MRR) and surface roughness (SR) of machining MMCs through two processes of EDM and AEDM. Attempting to receive the optimum process parameters of AEDM method, orthogonal experiment method is used to study the influence of MMC reinforced with different volume fraction phase on the machining efficiency. The experimental results show that the MMR and SR using AEDM method are better than those of EDM method. Moreover, effects of different process parameters on the machining efficiency are, from large to small, duty cycle, mean current, and pulse duration. This study also shows that the proportion of reinforced phase of the composite is one of the main factors affecting the machining efficiency.