In order to understand the fundamentals of a high energy vibrating type milling process, the energy transfer during me-chanical alloying of molybdenum disilicide is investigated based on the Magini-lasonna energy transfer method, amended by Murty.The efficiency factor and total energy of milling are calculated. MoSi2 synthesized by a mechanically induced self-propagating .reaction has also been studied according to different milling parameters, such as the number of balls and the ball to powder weight ratio. The results indicate that the efficiency factor is between 1.944 and 8.507 J/(g·s). A total milling energy of about 19.38-26.47 kJ/g is found to be necessary for the mechanically induced self-propagating reaction of a Mo:2Si powder mixture. The efficiency of milling energy transfer is about 3.3%-4.5%. The experiment and modeling show that the optimum condition for mechanical alloy-ing is a half full vial of balls.